The effects of auditory streaming on duplex perception

When a formant transition and the remainder of a syllable are presented to subjects' opposite ears, most subjects perceive two simultaneous sounds: a syllable and a nonspeech chirp. It has been demonstrated that, when the remainder of the syllable (base) is kept unchanged, the identity of the perceived syllable will depend on the kind of transition presented at the opposite ear. This phenomenon, called duplex perception, has been interpreted as the result of the independent operation of two perceptual systems or modes, the phonetic and the auditory mode. In the present experiments, listeners were required to identify and discriminate such duplex syllables. In some conditions, the isolated transition was embedded in a temporal sequence of capturing transitions sent to the same ear. This streaming procedure significantly weakened the contribution of the transition to the perceived phonetic identity of the syllable. It is likely that the sequential integration of the isolated transition into a sequence of capturing transitions affected its fusion with the contralateral base. This finding contrasts with the idea that the auditory and phonetic processes are operating independently of each other. The capturing effect seems to be more consistent with the hypothesis that duplex perception occurs in the presence of conflicting cues for the segregation and the integration of the isolated transition with the base.     

Assessing sex differences in behavioural flexibility in an endangered bird species: the Southern ground-hornbill (Bucorvus leadbeateri)

Animal Cognition - Since ecology influences the expression of cognitive traits, intra-specific variation in ecological demands can drive differences in cognition. This is often the case, for...     

Susceptibility to prosocial and antisocial influence in adolescence following mindfulness training

Mindfulness training programmes have shown to encourage prosocial behaviours and reduce antisocial tendencies in adolescents. However, less is known about whether training affects susceptibility to prosocial and antisocial influence. The current study investigated the effect of mindfulness training (compared with an active control) on self-reported prosocial and antisocial tendencies and susceptibility to prosocial and antisocial influence. 465 adolescents aged 11–16 years were randomly allocated to one of two training programmes. Pre- and post-training, participants completed a social influence task. Self-reported likelihood of engaging in prosocial and antisocial behaviours did not change post-training, and regardless of training group, participants showed a higher propensity for prosocial influence than for antisocial influence. Finally, participants were less influenced by antisocial ratings following both training programmes.     

Resetting the pitch-analysis system: 1. Effects of rise times of tones in noise backgrounds or of harmonics in a complex tone

The question of whether sudden increases in the amplitude of pure-tone components would perceptually isolate them from a more complex spectrum was investigated in two experiments. In Experiment 1, a 3.5-sec noise was played as a masker. During the noise, two pure-tone components of different frequencies appeared in succession. Subjects were asked to judge whether the pitch sequence went up or down. The rise time of these components had only a small and inconsistent effect on discrimination. In Experiment 2, the 3.5-sec background signal was a complex tone. The amplitudes of two of its components were incremented in succession. Again, subjects judged whether the pitch pattern went up or down. This time there was a sizable, monotonic effect of the rise time of the increments, with more rapid increments leading to better discrimination. The difference between the two results is interpreted in terms of the auditory system’s response to changing and unchanging signals and the role of its “sudden-change” responses in attracting perceptual processing to certain spectral regions.     

Auditory streaming and vertical localization: Interdependence of “what” and “where” decisions in audition

When a sequence of two tones is presented over headphones in an ascending or descending order of pitch, it is heard as correspondingly ascending or descending in space. The illusion of spatial change that accompanies pitch change can be induced onto a pair of noise bursts by presenting them in synchrony with the tones. When cues known to produce stream segregation are introduced, the perceived position of the noises is less influenced by the tones. Stream organization is seen to be implicated in the ability to separately localize concurrent sources of sound. This suggests that “what” and “where” decisions are highly interactive and that neurological evidence that suggests separate pathways for these decisions must be interpreted with caution.     

Playfulness and humor in the psychoanalytic relationship

This paper, which was presented at the Postgratuate Center for Mental Health, New York, February 10, 1990, is a much abbreviated version of Playfulness in the Psychoanalytic Relationship,Contemporary Psychoanalysis, 26(1), 74–95, 1990.