Exposure to a rhythmic auditory stimulus facilitates memory formation for the passive avoidance task in the day-old chick.

Previous research regarding the beneficial effects of auditory stimuli on learning and memory in humans has been inconsistent. In the current study, day-old chicks were used to reduce the impact of individual differences on responses. Chicks were trained on a passive avoidance task and exposed to various auditory stimuli. Exposure to a complex rhythmic sequence for 1 min strongly facilitated chicks' long-term memory. The optimal time of presentation of the stimulus was between 10 min before and 20 min after training. Moreover, the enhancing effect was not generalized to the other auditory stimuli tested. It is suggested that this effect may be due to arousal because arousal hormones are critical to long-term memory formation. This study indicates that the temporal characteristics and type of stimulus may be important considerations when investigating the effects of auditory stimuli on cognitive functioning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Variations in Intensity and Frequency Moderate the Facilitative Effects of a Complex Rhythm Stimulus on Long-Term Memory Consolidation in the Day-Old Chick (Callus gallus).

The authors have previously shown that exposure to 1 min of a complex, but not an isochronous, rhythm stimulus facilitates long-term memory consolidation in chicks (Gallus gallus) trained on a passive-avoidance task (S. R. Toukhsati & N. S. Rickard, 2001). The acoustic parameters of this stimulus were explored further in the current study. Retention was found to be best facilitated when the complex rhythm stimulus was presented at intensities between 5 and 15 dBA above background laboratory noise levels and at a frequency of 1 kHz. Removal of an accent from the stimulus did not moderate the effect. These findings provide confirmation that memory in an avian species can be facilitated by exposure to a complex rhythm stimulus and suggest that pattern repetition may be an important feature of this effect. (PsycINFO Database Record (c) 2010 APA, all rights reserved)