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.     

Friend or foe? The role of latent inhibition in predator and non-predator labelling by coral reef fishes

In communities of high biodiversity, the ability to distinguish predators from non-predators is crucial for prey success. Learning often plays a vital role in the ability to distinguish species that are threatening from those that are not. Many prey animals learn to recognise predators based on a single conditioning event whereby they are exposed to the unknown predator at the same time as alarm cues released from injured conspecifics. The remarkable efficiency of such learning means that recognition mistakes may occur if prey inadvertently learn that a species is a predator when it is not. Latent inhibition is a means by which prey that are pre-exposed to an unknown species in the absence of negative reinforcement can learn that the unknown animal is likely not a threat. Learning through latent inhibition should be conservative because mistakenly identifying predators as non-predators can have fatal consequences. In this study, we demonstrated that a common coral reef fish, lemon damselfish, Pomacentrus moluccensis can learn to recognise a predator as non-threatening through latent inhibition. Furthermore, we showed that we could override the latent inhibition effect by conditioning the prey to recognise the predator numerous times. Our results highlight the ability of prey fish to continually update the information regarding the threat posed by other fishes in their vicinity.     

Sex difference in subjective duration of looming and receding sounds

Looming sounds (sounds increasing in intensity over time) are more salient than receding sounds (a looming sound reversed in time). For example, they are estimated as being longer, louder, and more changing in loudness than receding sounds. Some authors interpret the looming salience as evolutionarily adaptive, because it increases the margins of safety of the perceiver in the case of preparatory behaviours (e.g., a motor reaction to an approaching sound source). Recently, Neuhoff et al (2009, Journal of Experimental Psychology: Human Perception and Performance 35 225-234) found that females more than males show overestimation of the spatiotemporal properties of virtually simulated looming sound sources. Here, I investigated whether the sex difference could be observed for the subjective duration of looming and receding sounds, and found that females more than males overestimate the duration of looming sounds in comparison to receding sounds.     

Audiovisual bounce-inducing effect: When sound congruence affects grouping in vision

Two disks moving from opposite points in space, overlapping, and stopping at one another’s starting point can be seen as either bouncing off one another or streaming through one another. With silent displays, observers report streaming, whereas, if a sound is played when the disks are in the overlap region, observers report bouncing. The change in perception is thought to be modulated by a lack of attention that inhibits the integration of the motion signal when disks overlap and by the sound that increases the congruence of the display, in comparison with a real elastic bounce. Here, we accompanied the disks’ motion with either a bounce-congruent sound (a billiard ball) or with bounce-incongruent sounds (a water drop, a firework). When the sound was switched on 200 msec before the disks’ overlap, (1) all the audiovisual displays induced more bounce responses than did the silent display, but (2) the bounce-congruent sound induced more bounce responses than did the bounceincongruent sounds. However, when the sound was switched on at the disks’ overlap, only the first result was observed. These results highlight both the role of attention and that of sound congruence.     

Beyond Conversation: Some Lessons for Nanoethics

One of the aims of the DEEPEN project was to deepen ethical understanding of issues related to emerging nanotechnologies through an interdisciplinary approach utilizing insights from philosophy, ethics, and the social sciences. Accordingly, part of its final report was dedicated to the question of what was accomplished with regards to this aim and what further research is required. It relates two insights: Nanotechnologies intensify the ambivalence of ongoing, long-term developments; and yet, our intuitions and received story-lines fail us as a guide to ethical and political matters concerning nanotechnologies.     

A Longitudinal Analysis of Psychiatric Severity upon Outcomes Among Substance Abusers Residing in Self-Help Settings

A longitudinal analysis of psychiatric severity was conducted with a national sample of recovering substance abusers living in Oxford Houses, which are self-run, self-help settings. Outcomes related to residents' psychiatric severity were examined at three follow-up intervals over one year. Over time, Oxford House residents with high versus low baseline psychiatric severity reported significantly more days using psychiatric medication, decreased outpatient psychiatric treatment, yet no significant differences for number of days abstinent and time living in an Oxford House. These findings suggest that a high level of psychiatric severity is not an impediment to residing in self-run, self-help settings such as Oxford House among persons with psychiatric comorbid substance use disorders.     

Change detection evokes a Simon-like effect

The present experiment studied choice response context effects on the programming of response sequences using behavioural and electrophysiological methods. Participants were asked to produce responses differing in sequence length (1-key vs. 3-key responses) with either their left or right hand in a choice reaction time (RT) task. The choice response context was manipulated by a blocked or mixed execution of 1-key and 3-key responses. A sequence length effect on RT was observed in the blocked but not in the mixed condition. The time course of the lateralized readiness potential indicates a motoric locus of the sequence length effect, suggesting that the response hand is activated before the entire motor program is established.     

From Vygotsky to Vygotskian psychology: introduction to the history of the Kharkov School

Around the end of the 1920s, Vygotsky introduced his integrative framework for psycho-logical research to the Soviet Union. This framework was not abandoned and forgotten until its rediscovery in Russia and America in the 1950s, as some claim. In fact, even after his untimely death in 1934, Vygotsky remained the spiritual leader of a group of his for-mer students and collaborators, who became known as the Kharkov School. This paper reconstructs the early intellectual history of Vygotskian psychology, as it emerged, around the time of Vygotsky's death, in the research program of the Kharkov School.