Behavioral Sciences

"We submitted three models to the competition which were based on the I-SAW model. The models introduced four new assumptions. In the first model an adjustment process was introduced through which the tendency for exploration was higher at the beginning and decreased over time in the exploration stage. Another new assumption was that surprise as a factor influencing the weight of a trial in the sampling procedure was
added. In the second model we added the possibility of an exclusion of unreliable experiences gained in the early trials of a game and the possibility of a revision of a reasonable alternative which was responsible for a very bad outcome in the previous trial. Three of the four added assumptions were combined in the third model. Because each of our models contains at least two new assumptions, we estimated the relative effect of each
assumption on the estimation and prediction scores and carried out a test of robustness. In this way, we were able to clarify the usefulness of each added assumption."

with force information. Multisensory interactions are ubiquitous in perception, even at early processing stages, and thus can potentially play a role in learning. In this study we explored humans' improvement on uni-sensory stiffness discrimination as a function of different sensory conditions and immediate knowledge of results (KR) during training. Two by two design was used: subjects were trained over two days on stiffness discrimination task with either matched visual-tactile, or tactile only stimuli and either with or without immediate feedback on their performance during training trials. Training resulted in both immediate but also latent, overnight learning in the proportion of correctly discriminated pairs of targets (PC), in all groups. Discrimination decision time (DT) gains were obtained only during practice, while between sessions partial deterioration was evident. Affordance of visual information during training blocks resulted in higher PC during training blocks, but lower PC in the haptic-only retests. This finding challenges the notion that long-term unisensory learning mechanisms operate optimally under multisensory training conditions, at least for the combination of the visual and haptic modalities. We training enhances discrimination ability in terms of PC. However, we found transient within-session effects of KR and visual-haptic trainings on DT: while visualhaptic training resulted in slower responses, KR training induced faster responses.

Perception of vibration during drilling demands
integration of haptic and auditory information with
force information. In this study we explored the ability
to detect and discriminate changes in vibrotactile
stimuli amplitude based either on purely haptic
feedback or together with congruent synthesized
auditory cues in groups of naive subjects and expert
surgeons. Our results point toward the complex
influence of multimodal experience during vibration
perception. First, in naive subjects, we showed that
detection and discrimination of amplitude change in
complex vibro-tactile stimulus is selectively sensitive to
combination of modality and previous experience. In
the domain of discrimination, our results suggest that
bi-modal performance is always better than uni-modal
performance regardless of order of experience.
Second, experiments with expert surgeons revealed
that expertise in complex skill of maxilla-facial surgery
strongly relies on enhanced touch perception, as
measured in reaction times and discrimination ability
in bi-modal vibro-auditory conditions. These
observations suggest that acquisition of mandibular
surgery skill has brought to an enhanced
representation of vibro-tactile modulations in relevant
stimuli ranges. Altogether, our results provide basis to
assume that during acquisition of mandibular drilling
skill, trainees may benefit from training of relevant
basic aspects of touch perception - sensitivity to
vibration and accompanying modulations of sound.

Previous research highlights four distinct contributors to the experience-description gap (the observation that people exhibit over-sensitivity to rare events in decisions from description, and the opposite bias in decisions from experience). These contributors include the nature of small samples, the mere presentation effect, the belief that the environment is dynamic, and over-generalization from decisions based on estimated risks. The current chapter reviews this research and highlights the role of a fifth contributor to the experience-description gap. Three new experiments demonstrate that long deliberation before the decisions increases the weighting of rare events. The increase, however, is not large. People tend to underweight rare events in decisions from experience even after a forced deliberation period of 7.8 second. This pattern was documented in pure decisions from experience, and when the subjects could rely on both description and experience. In addition, the results show that the existence of inter decisions delay does not increase the weighting of rare events when the subjects are asked to perform a distraction task during the delay. Distraction reduces the weighting of rare events.

Objective: In this study, we explored the time course of haptic stiffness discrimination learning and how it was affected by two experimental factors, the addition of visual information and/or knowledge of results (KR) during training.

Background: Stiffness perception may integrate both haptic and visual modalities. However, in many tasks, the visual field is typically occluded, forcing stiffness perception to be dependent exclusively on haptic information. No studies to date addressed the time course of haptic stiffness perceptual learning.

Method: Using a virtual environment (VE) haptic interface and a two-alternative forced-choice discrimination task, the haptic stiffness discrimination ability of 48 participants was tested across 2 days. Each day included two haptic test blocks separated by a training block. Additional visual information and/or KR were manipulated between participants during training blocks.

Results: Practice repetitions alone induced significant improvement in haptic stiffness discrimination. Between days, accuracy was slightly improved, but decision time performance was deteriorated. The addition of visual information and/or KR had only temporary effects on decision time, without affecting the time course of haptic discrimination learning.

Conclusion: Learning in haptic stiffness discrimination appears to evolve through at least two distinctive phases: A single training session resulted in both immediate and latent learning. This learning was not affected by the training manipulations inspected.

Application: Training skills in VE in spaced sessions can be beneficial for tasks in which haptic perception is critical, such as surgery procedures, when the visual field is occluded. However, training protocols for such tasks should account for low impact of multisensory information and KR.

The decision whether to explore new alternatives or to choose from familiar ones is implicit in many of our daily activities. How is this decision made? When will deviation from optimal exploration be observed? The current paper examines exploration decisions in the context of a multi-alternative “decisions from experience” task. In each trial, participants could choose a familiar option (the status quo) or a new alternative (risky exploration). The observed exploration rates were more sensitive to the frequent outcome from choosing new alternatives than to the average outcome. That is, the implicit decision whether to explore a new alternative reflects underweighting of rare events: Over-exploration was documented in "Rare Disasters" environments, and insufficient exploration was evident in "Rare Treasures" environments. In addition, the results reveal a decrease in exploration of new alternatives over time even when it is always optimal, and some exploration even when it is never reinforcing. These results can be captured with models that share a distinction between “data collection” and “outcome-driven” decision modes.  Under the data collection mode, the decision maker randomly collects information about the environment, to be used in future choices. Under the outcome-driven mode, the decision maker relies on small samples of previous experiences with familiar vs. unfamiliar alternatives, before the selection of a specific alternative. The predictive value of a 2-parameter “explorative sampler” quantification of these assumptions is demonstrated.

The stiffness properties of an environment are perceived during active manual manipulation primarily by processing force cues and position-based tactile, kinesthetic and visual information. Using a Two Alternative Forced Choice (2AFC) stiffness discrimination task, we tested how the perceiver integrates stiffness-related information based on sensory feedback from one or two modalities and the origins of within-session shifts in stiffness discrimination ability. Two factors were investigated: practice and the amount of available sensory information. Subjects discriminated between the stiffness of two targets that were presented either haptically or visual-haptically in two subsequent blocks. Our results show that prior experience in a unisensory haptic stiffness discrimination block greatly improved performance when visual feedback was subsequently provided along with the haptic feedback. This improvement could not be attributed to effects induced by practice or multisensory stimulus presentation. Our findings suggest that optimization integration theories of multi-sensory perception need to account for past sensory experience that may affect current perception of the task even within single session.

Exposure to uncontrollable outcomes was found to trigger learned helplessness: a state in which the agent fails to take advantage of regained control due to lack of exploration.  While the importance of this phenomenon has been widely studied, its underlying cause remains undetermined. One can learn not to explore because the environment is uncontrollable, because the average reinforcement is low or because rewards are rare.  The current paper presents a simple experimental paradigm that contrasts the predictions of the three contributors and offers a unified psychological mechanism that underlies the empirical phenomena. Our results demonstrate that learned helplessness is not correlated with either perceived controllability or the average reward, suggesting that reward prevalence is a better predictor of exploration behavior. A simple computational model where exploration decisions are based on small samples of past experiences captures the empirical phenomena while also providing a cognitive basis for feelings of uncontrollability.

► An incremental theory mutes the impact of attributions on attitudes and preferences. ► Exposure to situational attributions has positive effects for entity theorists. ► An attribution have a different meaning and impact depending on implicit theories. ► Blocking dispositional attributions toward a long-time adversary is possible.

No one likes feeling empty. When people feel empty they seek replenishment, which usually takes the form of increased self-focused behaviors that provide value to the self and decreased other-focused behaviors that provide value to others. This research demonstrates how exposure to the concept of emptiness by simply performing or observing acts of emptying (vs. filling or control) of a glass vase, coat pockets, a glass jar, or a duffle bag triggers the cognitive metaphor of resource deficiency. The resource deficiency metaphor in turn leads people to engage in self-focused behaviors such as eating candy or planning a dream vacation and to disengage from other-focused behaviors such as donating to charities or helping others.

Values are broad motivations that can serve as the basis for goals. We propose that values can be used to understand the motivational basis of amity goal orientation, a prosocial goal orientation within achievement situations. We offer theory and empirical evidence relating personal values to amity goal orientation and other achievement goal orientations. Specifically, the results of three studies and a mini meta-analysis suggest that the prosocial value of benevolence is positively related to amity goal orientation and can be interpreted as the motivational basis of amity goal orientation. Furthermore, power values are positively related to performance-approach goal orientation; selfdirection values are positively related to mastery goal orientation, and security values are positively related to performance-avoidance goal orientation. These findings can explain the pattern of correlations previously found among achievement goal orientations, and open up the potential for new research on amity goal orientation as well as other value-based achievement goal orientations.