Tool use in left brain damage and Alzheimer's disease: What about function and manipulation knowledge?

Tool use disorders are usually associated with difficulties in retrieving function and manipulation knowledge. Here, we investigate tool use (Real Tool Use, RTU), function (Functional Association, FA) and manipulation knowledge (Gesture Recognition, GR) in 17 left‐brain‐damaged (LBD) patients and 14 AD patients (Alzheimer disease). LBD group exhibited predicted deficit on RTU but not on FA and GR while AD patients showed deficits on GR and FA with preserved tool use skills. These findings question the role played by function and manipulation knowledge in actual tool use.     

Face processing is enhanced in the left and upper visual hemi-fields

We tested whether two known hemi-field asymmetries would affect visual search with face stimuli. Holistic processing of spatial configurations is better in the left hemi-field, reflecting a right hemisphere specialization, and object recognition is better in the upper visual field, reflecting stronger projections into the ventral stream. Faces tap into holistic processing and object recognition at the same time, which predicts better performance in the left and upper hemi-field, respectively. In the first experiment, participants had to detect a face with a gaze direction different from the remaining faces. Participants were faster to respond when targets were presented in the left and upper hemi-field. The same pattern of results was observed when only the eye region was presented. In the second experiment, we turned the faces upside-down, which eliminated the typical spatial configuration of faces. The left hemi-field advantage disappeared, showing that it is related to holistic processing of faces, whereas the upper hemi-field advantage related to object recognition persisted. Finally, we made the search task easier by asking observers to search for a face with open among closed eyes or vice versa. The easy search task eliminated the need for complex object recognition and, accordingly, the advantage of the upper visual field disappeared. Similarly, the left hemi-field advantage was attenuated. In sum, our findings show that both horizontal and vertical asymmetries affect the search for faces and can be selectively suppressed by changing characteristics of the stimuli.     

How does preference reversal appear and disappear? Effects of the evaluation mode

Preference reversal is a systematic change in the preference order between options when different response methods are used (e.g., choice vs. judgment). The present study focuses on procedures used to elicit preferences according to an evaluability hypothesis. Two experiments compared joint vs. separate evaluations and explicit vs. non‐explicit joint evaluations. Subjects had to express preferences between high‐variance gambles (HVGs) and low‐variance gambles (LVGs) either by choosing one gamble to play in a lottery or by assigning gambles minimum selling prices. We show that HVGs are preferred in both choice and pricing conditions when gambles are evaluated separately, and LVGs are preferred in both choice and selling conditions when gambles are evaluated in pairs: i.e., when the evaluation mode is held constant, classic preference reversal disappears. These results support the evaluability hypothesis, and suggest that preferences depend on whether subjects are allowed to compare the options they are asked to choose from or judge, independently of the nature of the scale (i.e., attractiveness vs. minimum selling price) they are required to adopt. Copyright © 2004 John Wiley & Sons, Ltd.     

Lexique 2: a new French lexical database.

In this article, we present a new lexical database for French: Lexique. In addition to classical word information such as gender, number, and grammatical category, Lexique includes a series of interesting new characteristics. First, word frequencies are based on two cues: a contemporary corpus of texts and the number of Web pages containing the word. Second, the database is split into a graphemic table with all the relevant frequencies, a table structured around lemmas (particularly interesting for the study of the inflectional family), and a table about surface frequency cues. Third, Lexique is distributed under a GNU-like license, allowing people to contribute to it. Finally, a metasearch engine, Open Lexique, has been developed so that new databases can be added very easily to the existing ones. Lexique can either be downloaded or interrogated freely from http://www.lexique.org.     

Tuberculosis detection by giant african pouched rats

In recent years, operant discrimination training procedures have been used to teach giant African pouched rats to detect tuberculosis (TB) in human sputum samples. This article summarizes how the rats are trained and used operationally, as well as their performance in studies published to date. Available data suggest that pouched rats, which can evaluate many samples quickly, are sufficiently accurate in detecting TB to merit further investigation as a diagnostic tool.     

The development of a phonological illusion: a cross-linguistic study with Japanese and French infants

In adults, native language phonology has strong perceptual effects. Previous work has shown that Japanese speakers, unlike French speakers, break up illegal sequences of consonants with illusory vowels: they report hearing abna as abuna. To study the development of phonological grammar, we compared Japanese and French infants in a discrimination task. In Experiment 1, we observed that 14-month-old Japanese infants, in contrast to French infants, failed to discriminate phonetically varied sets of abna-type and abuna-type stimuli. In Experiment 2, 8-month-old French and Japanese did not differ significantly from each other. In Experiment 3, we found that, like adults, Japanese infants can discriminate abna from abuna when phonetic variability is reduced (single item). These results show that the phonologically induced /u/ illusion is already experienced by Japanese infants at the age of 14 months. Hence, before having acquired many words of their language, they have grasped enough of their native phonological grammar to constrain their perception of speech sound sequences.     

Hot or cold: is communicating anger or threats more effective in negotiation?

Is communicating anger or threats more effective in eliciting concessions in negotiation? Recent research has emphasized the effectiveness of anger communication, an emotional strategy. In this article, we argue that anger communication conveys an implied threat, and we document that issuing threats is a more effective negotiation strategy than communicating anger. In 3 computer-mediated negotiation experiments, participants received either angry or threatening messages from a simulated counterpart. Experiment 1 showed that perceptions of threat mediated the effect of anger (vs. a control) on concessions. Experiment 2 showed that (a) threat communication elicited greater concessions than anger communication and (b) poise (being confident and in control of one's own feelings and decisions) ascribed to the counterpart mediated the positive effect of threat compared to anger on concessions. Experiment 3 replicated this positive effect of threat over anger when recipients had an attractive alternative to a negotiated agreement. These findings qualify previous research on anger communication in negotiation. Implications for the understanding of emotion and negotiation are discussed.     

Inducing changes in arousal and valence: Comparison of two mood induction procedures

This research examined the relative effectiveness of two mood induction procedures (MIPs) for inducing four specific moods varying along the dimensions of both valence and arousal. Participants were randomly assigned either to an autobiographical recall or to a music and guided imagery MIP and underwent a happiness, serenity, anger, or sadness mood induction. The findings confirmed the effectiveness of the two MIPs in producing changes on both the valence and arousal dimensions of mood. The results also revealed an unexpected greater efficiency of the autobiographical recall than of the combined procedure.     

An evaluation of psychophysical models of auditory change perception

In many psychophysical experiments, the participant's task is to detect small changes along a given stimulus dimension or to identify the direction (e.g., upward vs. downward) of such changes. The results of these experiments are traditionally analyzed with a constant-variance Gaussian (CVG) model or a high-threshold (HT) model. Here, the authors demonstrate that for changes along three basic sound dimensions (frequency, intensity, and amplitude-modulation rate), such models cannot account for the observed relationship between detection thresholds and direction-identification thresholds. It is shown that two alternative models can account for this relationship. One of them is based on the idea of sensory quanta; the other assumes that small changes are detected on the basis of Poisson processes with low means. The predictions of these two models are then compared against receiver operating characteristics (ROCs) for the detection of changes in sound intensity. It is concluded that human listeners' perception of small and unidimensional acoustic changes is better described by a discrete-state Poisson model than by the more commonly used CVG model or by the less favored HT and quantum models.