Human spatial navigation via a visuo-tactile sensory substitution system

Spatial navigation within a real 3-D maze was investigated to study space perception on the sole basis of tactile information transmitted by means of a 'tactile vision substitution system' (TVSS) allowing the conversion of optical images-collected by a micro camera-into 'tactile images' via a matrix in contact with the skin. The development of such a device is based on concepts of cerebral and functional plasticity, enabling subjective reproduction of visual images from tactile data processing. Blindfolded sighted subjects had to remotely control the movements of a robot on which the TVSS camera was mounted. Once familiarised with the cues in the maze, the subjects were given two exploration sessions. Performance was analysed according to an objective point of view (exploration time, discrimination capacity), as well as a subjective one (speech). The task was successfully carried out from the very first session. As the subjects took a different path during each navigation, a gradual improvement in performance (discrimination and exploration time) was noted, generating a phenomenon of learning. Moreover, subjective analysis revealed an evolution of the spatialisation process towards distal attribution. Finally, some emotional expressions seemed to reflect the genesis of 'qualia' (emotional qualities of stimulation).     

Teaching pigeons to commit base-rate neglect

Whereas humans display base-rate neglect in a behavioral analogue of the base-rate problem, pigeons have been shown to behave optimally in a comparable task, appropriately weighting base-rate and case-cue information. Previous studies have shown that prior experience may interfere with optimal decisions for human subjects, a result consistent with the position that poor and illogical decisions often follow from the misapplication of learned rules. The present study shows that pigeons will also display base-rate neglect if given extensive pretraining with informative case cues. Two experiments with pigeons, in a matching-to-sample procedure designed to mimic the classic base-rate problem, show that pigeons display base-rate neglect after extensive pretraining with the matching task.     

Using cognitive models to map relations between neuropsychological disorders and human decision-making deficits

Findings from a complex decision-making task (the Iowa gambling task) show that individuals with neuropsychological disorders are characterized by decision-making deficits that lead to maladaptive risk-taking behavior. This article describes a cognitive model that distills performance in this task into three different underlying psychological components: the relative impact of rewards and punishments on evaluations of options, the rate that the contingent payoffs are learned, and the consistency between learning and responding. Findings from 10 studies are organized by distilling the observed decision deficits into the three basic components and locating the neuropsychological disorders in this component space. The results reveal a cluster of populations characterized by making risky choices despite high attention to losses, perhaps because of difficulties in creating emotive representations. These findings demonstrate the potential contribution of cognitive models in building bridges between neuroscience and behavior.     

Constructed criteria: redefining merit to justify discrimination

This article presents an account of job discrimination according to which people redefine merit in a manner congenial to the idiosyncratic credentials of individual applicants from desired groups. In three studies, participants assigned male and female applicants to gender-stereotypical jobs. However, they did not view male and female applicants as having different strengths and weaknesses. Instead, they redefined the criteria for success at the job as requiring the specific credentials that a candidate of the desired gender happened to have. Commitment to hiring criteria prior to disclosure of the applicant's gender eliminated discrimination, suggesting that bias in the construction of hiring criteria plays a causal role in discrimination.     

How global versus local perception fits regulatory focus

We propose a reciprocal relation between regulatory-focus systems and global versus local processing styles-specifically, that global processing fits a promotion focus on advancement, whereas local processing fits a prevention focus on security. In Study 1, participants were shown large letters made of small letters and decided if either of two specific letters appeared on the screen. Strength of promotion focus was positively correlated with speed of processing global letters and negatively correlated with speed of processing local letters, whereas the reverse was true for strength of prevention focus. In Study 2, participants first worked on a global or local task and later chose between two objects. Consistent with our fit proposal, participants who had performed the global task assigned a higher price to their chosen object if they had chosen it in a promotive, eager manner than if they had chosen it in a preventive, vigilant manner, whereas the reverse was true for participants who had performed the local task.     

Word frequency of irrelevant speech distractors affects serial recall

In this study, participants memorized frequent or rare target words in silence or while ignoring frequent or rare distractor words. Distractor words impaired recall performance, but low-frequency distractor words caused more impairment than did high-frequency distractor words. We demonstrate how to solve the identifiability problem for Schweickert's (1993) multinomial processing tree model of immediate recall, and then use this model to show that irrelevant speech affected both the probability with which intact target word representations were available for serial recall and the probability of successful reconstruction of item identities based on degraded short-term memory traces. However, the type of irrelevant speech--low-versus high-frequency words--selectively affected the probability of intact target word representations. These results are consistent with an explanation of the irrelevant speech effect within the framework proposed by Cowan (1995), and they pose problems for other explanations of the irrelevant speech effect. The analyses also confirm the validity of Schweickert's process model.     

Muscular Activity in the Arm during Lexical Retrieval: Implications for Gesture-Speech Theories

The origin and functions of the hand and arm gestures that accompany speech production are poorly understood. It has been proposed that gestures facilitate lexical retrieval, but little is known about when retrieval is accompanied by gestural activity and how this activity is related to the semantics of the word to be retrieved. Electromyographic (EMG) activity of the dominant forearm was recorded during a retrieval task in which participants tried to identify target words from their definitions. EMG amplitudes were significantly greater for concrete than for abstract words. The relationship between EMG amplitude and other conceptual attributes of the target words was examined. EMG was positively related to a word’s judged spatiality, concreteness, drawability, and manipulability. The implications of these findings for theories of the relation between speech production and gesture are discussed.This experiment was done by the first author under the supervision of the second author in partial completion of the Ph.D. degree at Columbia University. We gratefully acknowledge the advice and comments of Lois Putnam, Robert Remez, James Magnuson, Michele Miozzo, and Robert B. Tallarico, and the assistance of Stephen Krieger, Lauren Walsh, Jennifer Kim, and Jillian White.     

Giving advice or making decisions in someone else's place: the influence of impression, defense, and accuracy motivation on the search for new information

When making decisions, people have been found predominantly to seek information supporting their preferred choice and to neglect conflicting information. In this article, the authors investigate to what extent different types of advisors, who recommend a choice to someone or make a decision on behalf of someone, show the same confirmatory information search. In Experiment 1, the authors presented participants, in the role of advisors, with a client's decision problem and found that when making a recommendation, advisors conducted a more balanced information search than participants who were making a decision for themselves. However, advisors who had to make a decision on behalf of their clients revealed an increased preference for information supporting their position. Experiment 2 suggested that this confirmatory information search was caused by impression motivation: The advisors bolstered their decision to justify it to the client. The results are discussed within the multiple motive framework of the heuristic systematic model.