Narrative framing may increase human suboptimal choice behavior.

Under certain conditions, multiple nonhuman species have been observed engaging in choice behavior that resulted in less food earned when compared to the amount of food that was available to be earned over the course of a session. This phenomenon is particularly strong in pigeons, but has also been observed in rats and nonhuman primates. Conversely, human participants have demonstrated a propensity to choose more optimally. However, human participants do not exclusively choose the alternative associated with more reinforcement. Framing a task in a real-world narrative has been effective in improving problem-solving on other tasks such as the Wason Four-Card problem. The present study gave human participants a choice task with either abstract stimuli or with a real-world narrative. In addition, participants were given terminal stimuli that were either predictive or unpredictive of reinforcement. Thus, participants were assigned to one of four conditions: Abstract Predictive, Abstract Unpredictive, Narrative Predictive, or Narrative Unpredictive. In contrast to the improved performance on the Wason Four-Card task, the current study found no evidence that the addition of a real-world narrative improved optimal choice performance. Rather, it may have interfered with optimal choice selection in that participants who received the narrative and unpredictive terminal stimuli were at chance performance at the end of the experimental session. Conversely, participants in the Abstract Unpredictive, Abstract Predictive, and Narrative Predictive conditions all demonstrated a preference for the optimal alternative. Possible mechanisms for these findings and future directions are discussed.

Human Choice Predicted by Obtained Reinforcers, Not by Reinforcement Predictors.

Macphail (1985) proposed that "intelligence" should not vary across vertebrate species when contextual variables are accounted for. Focusing on research involving choice behavior, the propensity for choosing an option that produces stimuli that predict the presence or absence of reinforcement but that also results in less food over time can be examined. This choice preference has been found multiple times in pigeons (Stagner and Zentall, 2010; Zentall and Stagner, 2011; Laude et al., 2014) and has been likened to gambling behavior demonstrated by humans (Zentall, 2014, 2016). The present experiments used a similarly structured task to examine adult human preferences for reinforcement predictors and compared findings to choice behavior demonstrated by children (Lalli et al., 2000), monkeys (Smith et al., 2017; Smith and Beran, 2020), dogs (Jackson et al., 2020), rats (Chow et al., 2017; Cunningham and Shahan, 2019; Jackson et al., 2020), and pigeons (Roper and Zentall, 1999; Stagner and Zentall, 2010). In Experiment 1, adult human participants showed no preference for reinforcement predictors. Results from Experiment 2 suggest that not only were reinforcement predictors not preferred, but that perhaps reinforcement predictors had no effect at all on choice behavior. Results from Experiments 1 and 2 were further assessed using a generalized matching equation, the findings from which support that adult human choice behavior in the present research was largely determined by reinforcement history. Overall, the present results obtained from human adult participants are different than those found from pigeons in particular, suggesting that further examination of Macphail (1985) hypothesis is warranted.

Testing principal- versus medial-axis accounts of global spatial reorientation.

Determination of a direction of travel is a necessary component of successful navigation, and various species appear to use the geometric shape (global geometric cues) of an environment to determine direction. Yet, debate remains concerning which objective shape parameter is responsible for spatial reorientation via global geometric cues. For example, the principal axis of space, which runs through the centroid and approximate length of the space, and the medial axis of space, a trunk and branch system that fills the shape, have each been suggested as a basis to explain global spatial reorientation. As the principal- and medial-axis accounts appear to have substantial theoretical implications regarding the nature of shape perception, spatial memory, and the underlying psychological representations of space, it appears critical to empirically differentiate between these global geometric accounts. The present experiment explicitly placed predictions from the principal- and medial-axis-based accounts of global spatial reorientation in conflict for theoretical diagnostic purposes. We used a standard reorientation paradigm in which human participants first reoriented in a rectangular environment; subsequent testing in a critical I-shaped enclosure allowed dissociation of the principal- or medial-axis-based accounts. We show that reorientation in the I-shaped enclosure was consistent with the principal-axis account and inconsistent with the medial-axis account. We suggest that the use of the principal axis for spatial reorientation is a relatively simple and efficient way to establish directionality that would be advantageous over a more complex and less efficient medial-axis-based account. (PsycINFO Database Record

Environmental scaling influences the use of local but not global geometric cues during spatial reorientation.

During spatial reorientation, the use of local geometric cues (e.g., corner angles) and global geometric cues (e.g., principal axis) is differentially influenced by enclosure size. Local geometric cues exert more influence in large enclosures compared to small enclosures, whereas the use of global geometric cues is not influenced by changes in enclosure size. Such effects are suggested to occur because of differences in training enclosures sizes or differences in testing enclosure sizes, but investigations of enclosure-size effects on spatial cue use have been confounded by environmental scaling between training and testing. We trained participants in a trapezoid-shaped enclosure to respond to a corner uniquely specified by both local and global geometric cues and tested participants in a rectangle (isolating the use of global geometric cues) and in a parallelogram (placing local and global geometric cues in conflict). Between groups, participants experienced different training environment sizes but identical testing environment sizes or identical training environment sizes but different testing environment sizes, and this allowed categorization with respect to the direction of environmental scaling. We found that environmental scaling between training and testing size (but not training size differences or testing size differences) influenced the relative use of local geometric cues. The use of global geometric cues was not influenced by enclosure size. Results challenge prior explanations of the influence of enclosure size on relative spatial cue use during spatial reorientation. (PsycINFO Database Record

Detecting the perception of illusory spatial boundaries: Evidence from distance judgments.

Spatial boundaries demarcate everything from the lanes in our roadways to the borders between our countries. They are fundamental to object perception, spatial navigation, spatial memory, spatial judgments, and the coordination of our actions. Although explicit spatial boundaries formed by physical structures comprise many of the actual boundaries we encounter, implicit and permeable spatial boundaries are pervasive. The prevailing paradigm for detecting implicit spatial boundaries relies on memory-based distance and location judgments. One possibility is that these biases in spatial memory may be attributable to initial biases in spatial perception, but the extent to which implicit spatial boundaries bias spatial perception remains unknown. An approach for detecting the perception of implicit spatial boundaries would be to infer it through known systematic biases in memory-based distance judgments. We harnessed known biases in memory-based distance judgments to infer perception of spatial boundaries by probing the extent to which distances were overestimated across potential spatial boundaries. Results suggest that participants perceived potential spatial boundaries as illusory spatial boundaries leading to biased judgments of distance. A control group eliminated simple two-dimensional distance cues as responsible for this bias. This bias provides a novel method to detect the perception of illusory spatial boundaries.

Evidence consistent with the multiple-bearings hypothesis from human virtual landmark-based navigation.

One approach to explaining the conditions under which additional landmarks will be learned or ignored relates to the nature of the information provided by the landmarks (i.e., distance versus bearings). In the current experiment, we tested the ability of such an approach to explain the search behavior of human participants in a virtual landmark-based navigation task by manipulating whether landmarks provided stable distance, stable direction, or both stable distance and stable direction information. First, we incrementally shaped human participants' search behavior in the presence of two ambiguous landmarks. Next, participants experienced one additional landmark that disambiguated the location of the goal. Finally, we presented three additional landmarks. In a control condition, the additional landmarks maintained stable distances and bearings to the goal across trials. In a stable bearings condition, the additional landmarks varied in their distances but maintained fixed bearings to the goal across trials. In a stable distance condition, the additional landmarks varied in their bearings but maintained fixed distances to the goal across trials. Landmark stability, in particular, the stability of landmark-to-goal bearings, affected learning of the added landmarks. We interpret the results in the context of the theories of spatial learning that incorporate the nature of the information provided by landmarks.

Does constraining field of view prevent extraction of geometric cues for humans during virtual-environment reorientation?

Environment size has been shown to influence the reliance on local and global geometric cues during reorientation. Unless changes in environment size are produced by manipulating length and width proportionally, changes in environment size are confounded by the amount of the environment that is visible from a single vantage point. Yet, the influence of the amount of the environment that is visible from any single vantage point on the use of local and global geometric cues remains unknown. We manipulated the amount of an environment that was visually available to participants by manipulating field of view (FOV) in a virtual environment orientation task. Two groups of participants were trained in a trapezoid-shaped enclosure to find a location that was uniquely specified by both local and global geometric cues. One group (FOV 50°) had visually less of the environment available to them from any one perspective compared to another group (FOV 100°). Following training, we presented both groups with a control test along with three novel-shaped environments. Testing assessed the use of global geometry in isolation, in alignment with local geometry, or in conflict with local geometry. Results (confirmed by a follow-up experiment) indicated that constraining FOV prevented extraction of geometric properties and relationships of space and resulted in an inability to use either global or local geometric cues for reorientation.

Beacons and surface features differentially influence human reliance on global and local geometric cues when reorienting in a virtual environment.

In the reorientation literature, non-geometric cues include discrete objects (e.g., beacons) and surface-based features (e.g., colors, textures, and odors). To date, these types of non-geometric cues have been considered functionally similar, and it remains unknown whether beacons and surface features differentially influence the extent to which organisms reorient via global and local geometric cues. In the present experiment, we trained human participants to approach a location in a trapezoid-shaped enclosure uniquely specified by global and local geometric cues. We explored the role of beacons on the use of geometric cues by training participants in the presence or absence of uniquely-colored beacons. We explored the role of surface features on the use of geometric cues by recoloring two adjacent walls at the correct location and/or adding a line on the floor which corresponded to the major principal axis of the enclosure. All groups were then tested in novel-shaped enclosures in the absence of unique beacons and surface features to assess the relative use of global and local geometric cues. Results suggested that beacons facilitated the use of global geometric cues, whereas surface features either facilitated or hindered the use of geometric cues, depending on the feature.

Overtraining and the use of feature and geometric cues for reorientation.

Using a dynamic three-dimensional virtual environment task, we investigated the influence of overtraining of feature and geometric cues on preferential spatial cue use. We trained two groups of human participants to respond to feature and geometric cues in separate enclosures before placing these cues in conflict on a critical test trial. All participants learned to respond to rewarded features located along the principal axis of a rectangular search space and to rewarded geometric cues of a rectangular search space in separate training phases followed by a single test trial. During the test trial, we situated the rewarded features in the unrewarded geometric corners and the unrewarded features in rewarded geometric corners. For one group, participants were overtrained with feature cues compared to geometric cues before experiencing the conflict test; whereas, for another group, participants were overtrained with geometric cues compared to feature cues before experiencing the conflict test. Although both groups learned to respond to both feature and geometric cues at an equivalent rate and to an equivalent level of terminal accuracy, testing results revealed no difference between the groups with respect to their preference for feature or geometric cues. Despite a lack of influence of overtraining on spatial cue preference, participants showed an overall preference for feature cues. We discuss the results with respect to implications for theoretical accounts of spatial learning.

On Discriminating between Geometric Strategies of Surface-Based Orientation.

Recently, a debate has manifested in the spatial learning literature regarding the shape parameters by which mobile organisms orient with respect to the environment. On one hand are principal-axis-based strategies which suggest that organisms extract the major and minor principal axes of space which pass through the centroid and approximate length and width of the entire space, respectively. On the other hand are medial-axis-based strategies which suggest that organisms extract a trunk-and-branch system similar to the skeleton of a shape. With competing explanations comes the necessity to devise experiments capable of producing divergent predictions. Here, we suggest that a recent experiment (i.e., Sturz and Bodily, 2011a) may be able to shed empirical light on this debate. Specifically, we suggest that a reevaluation of the design reveals that the enclosures used for training and testing appear to produce divergent predictions between these strategies. We suggest that the obtained data appear inconsistent with a medial-axis-based strategy and that the study may provide an example of the types of designs capable of discriminating between these geometric strategies of surface-based orientation. Such an approach appears critical to fundamental issues regarding the nature of space and spatial perception.

No evidence that consistent auditory cues facilitate learning of spatial relations among locations.

Human participants searched in a dynamic three-dimensional computer-generated virtual-environment open-field search task for four hidden goal locations arranged in a diamond configuration located in a 5×5 matrix of raised bins. Participants were randomly assigned to one of two groups: Consistent or Inconsistent. All participants experienced 30 trials in which four goal locations maintained the same spatial relations to each other (i.e., a diamond pattern), but this diamond pattern moved to random locations within the 5×5 matrix from trial-to-trial. For participants in the Consistent group, each goal location within the pattern always provided a unique and consistent auditory cue throughout the experimental session. For participants in the Inconsistent group, the same distinct auditory cues were provided for each goal location; however, the locations of these auditory cues within the pattern itself were randomized from trial-to-trial throughout the experimental session. Results indicated that participants in both groups learned the spatial configuration of goal locations, but the presence of consistent auditory cues did not facilitate the learning of spatial relations among locations.

Enclosure size and the use of local and global geometric cues for reorientation.

Multiple spatial cues are utilized to orient with respect to the environment, but it remains unclear why feature (i.e., objects in the environment) and geometric (i.e., shape of the environment) cues are differentially influenced by enclosure size, and the extent to which local (i.e., wall lengths and corner angles) and global (i.e., principal axis of space) geometric cues are influenced by enclosure size. In the present study, we investigated the extent to which environmental size influenced the use of corner angle (i.e., a local geometric cue) and the principal axis of space (i.e., a global geometric cue) for reorientation. We developed an orientation task that allowed the manipulation of enclosure size during training and the isolation of the use of the principal axis of space during testing. Participants were trained to respond to a location in either a small or a large trapezoid-shaped enclosure uniquely specified by both local (i.e., wall lengths and corner angles) and global (i.e., principal axis of space) geometric cues. During testing, we presented both groups with a small and large rectangle (to assess the use of principal axis of space) and a small and large parallelogram (to asses relative use of corner angles and the principal axis of space when in conflict). Enclosure size influenced the relative use of corner angles but not of the principal axis of space. Results suggest that corner angles function like features and that changes in the use of feature cues are the source of the relative reliance on feature and geometric cues during changes of enclosure size.

Solving for two unknowns: an extension of vector-based models of landmark-based navigation.

Vectors are mathematical representations of distance and direction information that take the form of line segments where length represents distance and orientation in space represents direction. Vector-based models have proven beneficial in understanding the spatial behavior of a variety of species in tasks that require landmark-based navigation via vector addition and vector averaging to determine a location. Extant research regarding vector-based representational and computational accounts of landmark-based navigation has involved tasks that required solving for one unknown (i.e., a location). Using a novel landmark-based navigation task, we provide evidence consistent with a form of vector algebra that involves solving two simultaneous equations with two unknowns in order to determine a location in space. Results extend vector-based accounts of landmark-based navigation and provide a novel methodological approach to the testing of mobile organisms.

Is surface-based orientation influenced by a proportional relationship of shape parameters?

We investigated the extent to which parameters of environmental shape - namely the major and minor principal axes of space which pass through the centroid and approximate length and width of the entire space, respectively, were subject to similar psychophysical principles as those involved in distance discriminations. We developed an orientation task that allowed us to manipulate the ratio of the major to the minor principal axes of an enclosure during training and control for orientation by alternative cues other than principal axes such as wall lengths or corner angles during testing. Participants trained in an environment with a larger hypothetical discriminability ratio allocated more responses to locations specified by the principal axes of space across novel enclosure types compared to a group trained with a smaller hypothetical discriminability ratio. Results suggest that psychophysical principles may operate on the discrimination of environmental shape parameters and delineate a potential mechanism for experiential and developmental changes in orientation ability.

Neither by global nor local cues alone: evidence for a unified orientation process.

A substantial amount of empirical and theoretical debate remains concerning the extent to which an ability to orient with respect to the environment is determined by global (i.e., principal axis of space), local (i.e., wall lengths, angles), and/or view-based (i.e., stored representation) accounts. We developed an orientation task that allowed the manipulation of the reliability of the principal axis of space (i.e., searching at the egocentric left- and/or right-hand side of the principal axis) between groups while maintaining goal distance from the principal axis, local cues specifying the goal location (i.e., short wall left, short wall right, and obtuse angle), and visual aspects of the goal location consistent across groups. Control and test trials revealed that participants trained with a reliable principal axis of space utilized both global and local geometric cues, whereas those trained with an unreliable principal axis of space utilized only local geometric cues. Results suggest that both global and local geometric cues are utilized for reorientation and that the reliability of the principal axis of an enclosure differentially influences the use of geometric cues. Such results have implications for purely global-based, purely local-based, and purely view-based matching theoretical accounts of geometry learning and provide evidence for a unified orientation process.

Orientation in trapezoid-shaped enclosures: implications for theoretical accounts of geometry learning.

Human participants learned to select 1 of 4 distinctively marked corners in a rectangular virtual enclosure. After training, control and test trials were interspersed with training trials. On control and test trials, all markers were equivalent in color, but only during test trials was the shape of the enclosure manipulated. Specifically, for each test trial, a single long wall or short wall of the enclosure increased twice as long as or decreased half as long as that present in the training enclosure. These manipulations produced 8 unique trapezoid-shaped enclosures. Participants were allowed to select 1 corner during control and test trials. Performance during control trials revealed that participants selected the correct and rotationally equivalent locations. Performance during test trials revealed that participants selected locations in trapezoid-shaped enclosures that were consistent with those predicted by global geometry (i.e., principal axis of space) but were inconsistent with those predicted by local geometry (i.e., proportion of rewarded training features present at a location). Results have implications for theoretical accounts of geometry learning.

Encoding of variability of landmark-based spatial information.

Recent evidence suggests humans optimally weight visual and haptic information (i.e., in inverse proportion to their variances). A more recent proposal is that spatial information (i.e., distance and direction) may also adhere to Bayesian principles and be weighted in an optimal fashion. A fundamental assumption of this proposal is that participants encode the variability of spatial information. In a three-dimensional virtual-environment open-field search task, we provide evidence that participants encoded the variability of landmark-based spatial information. Specifically, participants searched for a hidden goal location in a 5 × 5 matrix of raised bins. Participants experienced five training phases in which they searched for a hidden goal that maintained a unique spatial relationship to each of four distinct landmarks. Each landmark was assigned an a priori value of locational uncertainty such that each varied in its ability to predict a goal (i.e., varied in number of potential goal locations). Following training, participants experienced conflict trials in which two distinct landmarks were presented simultaneously. Participants preferentially responded to the landmark with the lower uncertainty value (i.e., smaller number of potential goal locations). Results provide empirical evidence for the encoding of variability of landmark-based spatial information and have implications for theoretical accounts of spatial learning.

Dissociation of past and present experience in problem solving using a virtual environment.

An interactive 3D desktop virtual environment task was created to investigate learning mechanisms in human problem solving. Participants were assessed for previous video game experience, divided into two groups (Training and Control), and matched for gender and experience. The Training group learned specific skills within the virtual environment before being presented a problem. The Control group was presented the problem only. Completion time was faster for the Training group and was affected by level of previous video game experience. Results indicated problem solving was a function of specific and general experience and demonstrated a method for dissociating these two facets of experience.

Abstract-concept learning carryover effects from the initial training set in pigeons (Columba livia).

Three groups of pigeons were trained in a same/different task with 32, 64, or 1,024 color-picture stimuli. They were tested with novel transfer pictures. The training-testing cycle was repeated with training-set doublings. The 32-item group learned the same/different task as rapidly as a previous 8-item group and transferred better than the 8-item group at the 32-item training set. The 64- and 1,024-item groups learned the task only somewhat slower than other groups, but their transfer was better and equivalent to baseline performances. These results show that pigeons trained with small sets (e.g., 8 items) have carryover effects that hamper transfer when the training set is expanded. Without carryover effects (i.e., initial transfer from the 32- and 64-item groups), pigeons show the same degree of transfer as rhesus and capuchin monkeys at these same set sizes. This finding has implications for the general ability of abstract-concept learning across species with different neural architectures.