Red herring detectors and speech perception: In defense of selective adaptation

The selective adaptation paradigm was used extensively for about 5 years following its introduction to speech research in 1973. During the next few years, its use dropped dramatically; it is now little used. Several reasons for the abandonment of the paradigm are discussed, and theoretical and empirical justification is provided for rejecting these reasons. Experiment 1 demonstrates that “acoustic similarity” of an adapting sound and test items cannot account for the observed results. Experiments 2–4 demonstrate that adaptation effects are not equivalent to simple contrast effects. These experiments indicate that selective adaptation produces robust reaction time effects—items in the adapted category are identified more slowly than unadapted items. The effects found in a simple paired-contrast procedure differ from those found with selective adaptation. Most strikingly, contrast effects are extremely ear dependent—much larger effects occur if testing is conducted in the right ear than in the left; adaptation effects are relatively symmetrical with respect to ear. The empirical and theoretical analyses suggest that the selective adaptation paradigm can be a powerful tool for investigating the perception of complex acoustic stimuli like speech.     

An expert–novice comparison of feature choice

Perceptual experts have learned to rapidly and accurately perceive the structural regularities that define categories and identities within a domain. They extract important features and their relations more efficiently than novices. We used fingerprint examination to investigate expert–novice differences in feature choice. On each fingerprint within our set, experts and novices selected one feature they thought was most useful for distinguishing a particular print and one feature they thought was least useful. We found that experts and novices often differed in the features they chose, and experts tended to agree more with each other. However, any such expert–novice difference appeared to depend on the image at hand typically emerging when salient or more conspicuous features of a fingerprint were unclear. We suggest that perceptual training ought to direct attention to useful features with the understanding that what is useful may change depending on the clarity of the stimuli.     

Chlordiazepoxide and the moderation of the initial response to reward reduction

The effectiveness of chlordiazepoxide (CDP) in reducing negative contrast on the first day after a shift from 32% to 4% sucrose was investigated in four experiments using rats. Previous studies indicated that CDP was effective on the second, but not on the first postshift day. In Experiments 1 and 1a, neither initial experience (3 or 10 days) with the eventual postshift 4% solution (i.e. 4%, then 32%, then 4%), nor initial experience with alternating 4% and 32% sucrose, led to a reliable contrast-reducing effect of CDP on the first shift day. Evidence from Experiments 2 and 3 suggested that a range of doses of CDP (3, 5, 10, and 15 mg/kg) did not have reliable effects on the first postshift day, although the two lower doses did reduce contrast on the second postshift day (the higher doses were not administered on Day 2). The evidence suggests that the relative ineffectiveness of CDP in moderating the initial response to reward reduction is not related to a problem of recognizing the difference between the postshift solution and the memory of the preshift solution. Alternative interpretations in which CDP's lack of effect on the initial occurrence of contrast is related to an initial stage of unconditioned frustration and/or exploratory behaviour are considered.     

What’s in a Name? The Dilemma of Title and Geography for Contemporary Hasidism

This paper examines the importance of “branding” in hasidic life. It considers the impact of place names associated with the title of a particular rebbe or tsadik and his followers. When there is more than one claimant to succeed to the role of rebbe for a particular group of hasidim, the competition is often intensified because even though each claimant may have his own followers, there is only one name available for the group and its leader. This situation, different from the one that existed earlier in the history of Hasidism, makes the circumstances of succession today more fraught than they once were.