Sex Differences in Delayed Matching-to-Sample Performance of Chimpanzees

1975 ◽  
Vol 37 (1) ◽  
pp. 203-207 ◽  
Author(s):  
David M. Grilly
Keyword(s):  
Rhesus Monkeys ◽  
Short Term Memory ◽  
Extended Period ◽  
Matching To Sample ◽  
Short Term ◽  
Delayed Matching ◽  
Delayed Matching To Sample ◽  
Sample Technique ◽  
Retention Intervals ◽  
Significant Superiority

The short-term memory for visual stimuli was tested in 17 chimpanzees, 7 females and 10 males, with the delayed matching-to-sample technique. A statistically significant superiority of females in matching accuracy was exhibited over an extended period of time and under at least two different retention intervals. The results were consistent with those obtained with rhesus monkeys on similar tasks. The possibility that this difference was attributable to factors other than experience was suggested.

Sustained and transient oscillatory responses in the gamma and beta bands in a visual short-term memory task in humans

1999 ◽  
Vol 16 (3) ◽  
pp. 449-459 ◽  
Author(s):  
CATHERINE TALLON-BAUDRY ◽  
ANDREAS KREITER ◽  
OLIVIER BERTRAND
Keyword(s):  
Evoked Potentials ◽  
Short Term Memory ◽  
Memory Task ◽  
Matching To Sample ◽  
Short Term ◽  
Term Memory ◽  
Delayed Matching ◽  
Delayed Matching To Sample ◽  
Visual Short Term Memory ◽  
Delay Duration

In a visual delayed matching-to-sample task, compared to a control condition, we had previously identified different components of the human EEG that could reflect the rehearsal of an object representation in short-term memory (Tallon-Baudry et al., 1998). These components were induced oscillatory activities in the gamma (24–60 Hz) and beta (15–20 Hz) bands, peaking during the delay at occipital and frontal electrodes, and two negativities in the evoked potentials. Sustained activities (lasting until the end of the delay) are more likely to reflect the continuous rehearsing process in memory than transient (ending before the end of the delay) activities. Nevertheless, since the delay duration we used in our previous experiment was fixed and rather short, it was difficult to discriminate between sustained and transient components. Here we used the same delayed matching-to-sample task, but with variable delay durations. The same oscillatory components in the gamma and beta bands were observed again during the delay. The only components that showed a sustained time course compatible with a memory rehearsing process were the occipital gamma and frontal beta induced activities. These two activities slowly decreased with increasing delay duration, while the performance of the subjects decreased in parallel. No sustained response could be found in the evoked potentials. These results support the hypothesis that objects representations in visual short-term memory consist of oscillating synchronized cell assemblies.

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