Stimulus control by same-versus-different relations among multiple visual stimuli.

Young gulls exposed to a moving silent pendulum subsequently selected the familiar stimulus in a choice test, indicating the suitability of pendulums as visual imprinting stimuli for this species.On their 3rd and 4th days post hatch, imprinted gulls were given 2 h of training exposure to either the visual imprinting stimulus (control), an adult "mew" call, or a combination of the two. Some were trained with the call of another species, Larus bulleri. All birds were tested to determine the effects of training on responsiveness to the mew calls when these were presented alone.During testing, the birds that had received training exposure to the visual stimuli or to both the auditory and visual stimuli responded at relatively high levels to the test calls. Birds that were trained with the auditory stimuli alone responded significantly less to the test calls. These results suggest that responsiveness to parental calls declines upon repeated post-hatch exposure to them, but this decline is ameliorated if the birds are exposed to calls in the presence of visual imprinting stimuli. Further analyses of the data revealed that responsiveness during training tended to be maintained at the highest levels when the conspecific call was presented.

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Consistency in the strength of laterality in male, but not female, guppies across different behavioural contexts

Biology Letters ◽

10.1098/rsbl.2019.0870 ◽

2020 ◽

Vol 16 (5) ◽

pp. 20190870

Author(s):

Stephanie McLean ◽

Lesley J. Morrell

Keyword(s):

Sex Differences ◽

Stimulus Control ◽

Poecilia Reticulata ◽

Visual Stimuli ◽

Substantial Variation ◽

Selection Pressures ◽

Brain Functions ◽

Opposite Sex

Laterality, the division of brain functions into separate hemispheres, is widespread across animal taxa. Lateralized individuals exhibit cognitive advantages yet substantial variation in laterality exists, particularly between the sexes. Why variation is maintained is unknown as few studies consider differences in lateralized behaviours between the sexes, and their underlying selection pressures, across different contexts. We investigated if Poecilia reticulata exhibited sex differences in the direction, strength and consistency of lateralization. We assessed the turning preferences of individuals detouring around a barrier to view visual stimuli representative of different behavioural contexts: an artificial object of familiar colour, an opposite sex conspecific and a no stimulus control. While no sex differences were evident in the direction or strength of laterality, consistency in the strength of laterality varied between the sexes. Individuals of both sexes consistently detoured in one direction, but the strength of laterality exhibited by males was more predictable than females across contexts. This suggests that predictability of lateralization across ecologically relevant scenarios represents a key, but previously unexplored, source of variation between the sexes.

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Temporal regularity and stimulus control in multiple fixed interval schedules

10.1101/695353 ◽

2019 ◽

Author(s):

Estela B. Nepomoceno ◽

André M. Cravo ◽

Marcelo B. Reyes ◽

Marcelo S. Caetano

Keyword(s):

Stimulus Control ◽

Visual Stimuli ◽

Fixed Interval ◽

Schedules Of Reinforcement ◽

Time Intervals ◽

Temporal Regularity ◽

Temporal Cues ◽

Temporal Aspects ◽

External Stimuli ◽

Block Experiment

AbstractIn multiple fixed interval schedules of reinforcement, different time intervals are signaled by different environmental stimuli which acquire control over behavior. Previous work has shown that temporal performance is controlled not only by external stimuli but also by temporal aspects of the task, depending on the order in which the different intervals are trained – intermixed across trials or in blocks of several trials. The aim of this study was to further describe the training conditions under which the stimuli acquire control over temporal performance. We manipulated the number of consecutive trials of each fixed interval (FI) per training block (Experiment I) and the number of FIs trained (Experiment II). The results suggest that when trained in blocks of several consecutive trials of the same FI, temporal performance is controlled by temporal regularities across trials and not by the visual stimuli that signal the FIs. One possible account for those data is that the temporal cues overshadow the visual stimuli for the control of temporal performance. Similar results have also been observed with humans, which suggest that temporal regularity overcomes the stimuli in the control of behavior in temporal tasks across species.

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