Human Behavior in Suboptimal Choice Tasks: Defining Optimality.

Suboptimal choice behavior, or behavior that leads to a loss of resources over time, has been observed in a laboratory setting from multiple species. A procedure commonly used to capture this effect involves presenting two alternatives during choice trials, one of which is optimal whereas the other is suboptimal. The optimal alternative yields reinforcement more often than the suboptimal alternative, but often does not produce signals that indicate whether reinforcement will occur.

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.

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.

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.

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.

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.

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).

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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).

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.

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.

Evidence against integration of spatial maps in humans: generality across real and virtual environments.

A real-world open-field search task was implemented with humans as an analogue of Blaisdell and Cook's (Anim Cogn 8:7-16, 2005) pigeon foraging task and Sturz, Bodily, and Katz's (Anim Cogn 9:207-217, 2006) human virtual foraging task to 1) determine whether humans were capable of integrating independently learned spatial maps and 2) make explicit comparisons of mechanisms used by humans to navigate real and virtual environments. Participants searched for a hidden goal located in one of 16 bins arranged in a 4 x 4 grid. In Phase 1, the goal was hidden between two landmarks (blue T and red L).

Matching-to-sample abstract-concept learning by pigeons.

Abstract concepts--rules that transcend training stimuli--have been argued to be unique to some species. Pigeons, a focus of much concept-learning research, were tested for learning a matching-to-sample abstract concept. Five pigeons were trained with three cartoon stimuli.

Learning strategies in matching to sample: if-then and configural learning by pigeons.

Pigeons learned a matching-to-sample task with a split training-set design in which half of the stimulus displays were untrained and tested following acquisition. Transfer to the untrained displays along with no novel-stimulus transfer indicated that these pigeons learned the task (partially) via if-then rules. Comparisons to other performance measures indicated that they also partially learned the task via configural learning (learning the gestalt of the whole stimulus display).

Issues in the Comparative Cognition of Abstract-Concept Learning.

-concept learning, including same/different and matching-to-sample concept learning, provides the basis for many other forms of "higher" cognition. The issue of which species can learn abstract concepts and the extent to which abstract-concept learning is expressed across species is discussed. Definitive answers to this issue are argued to depend on the subjects' learning strategy (e.