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Behavior is often linked to gonadal sex; however, ecological or social environments can induce plasticity in sex-biased behaviors. In biparental species, pairs may divide offspring care into two parental roles, in which one parent specializes in territory defense and the other in nest care. The African cichlid fish Julidochromis marlieri displays plasticity in sex-biased behaviors. In Lake Tanganyika, J. marlieri form female-larger pairs in which the female is more aggressive than the male who performs more nest care, but under laboratory conditions, male-larger pairs can be formed in which these sex-biased behaviors are reversed. We investigated the influence of social environment on behavior by observing how individuals in both pair-types respond to conspecific intruders of either sex. We examined behavioral responses to three factors: sex of the subject, relative size of the subject, and the sex of the intruder. We confirm that relative size is a factor in behavior. The larger fish in the pair is more aggressive than the smaller fish is towards an intruder. While neither fish in the female-larger pairs varied their behaviors in response to the sex of the intruder, both members of the male-larger pairs were sensitive to intruder sex. Both individuals in the male-larger pairs engaged in more biting behaviors towards the intruder. Intruder biting behaviors strongly correlated with the biting behavior of the larger individual in the pair and occurred more frequently when encountering pairs with same sex as the larger fish when compared to pairs with the same sex as the smaller fish. Our results support the role of the social environment as a contributor in the expression of sex-biased behavior.
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Tasks determine what is learned in visual statistical learning
Visual statistical learning (VSL), the unsupervised learning of statistical contingencies across time and space, may play a key role in efficient and predictive encoding of the perceptual world. How VSL capabilities vary as a function of ongoing task demands is still poorly understood. VSL is modulated by selective attention and faces interference from some secondary tasks, but there is little evidence that the types of contingencies learned in VSL are sensitive to task demands. We found a powerful effect of task on what is learned in VSL. Participants first completed a visual familiarization task requiring judgments of face gender (female/male) or scene location (interior/exterior). Statistical regularities were embedded between stimulus pairs. During a surprise recognition phase, participants showed less recognition for pairs that had required a change in response key (e.g., female followed by male) or task (e.g., female followed by indoor) during familiarization. When familiarization required detection of "flicker" or "jiggle" events unrelated to image content, there was weaker, but uniform, VSL across pair types. These results suggest that simple task manipulations play a strong role in modulating the distribution of learning over different pair combinations. Such variations may arise from task and response conflict or because the manner in which images are processed is altered.
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- PAR ID:
- 10058245
- Date Published:
- Journal Name:
- Psychonomic Bulletin & Review
- ISSN:
- 1069-9384
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.3758/s13423-017-1405-6
