The effect of prior recall on multiple response recognition

Certain investigators have found that recognition is impaired when a recall test is interpolated during the retention interval. One possible explanation of this finding is that interpolated recall leads subjects to employ a more stringent recognition criterion. In the two experiments reported here, the influence of the recognition criterion was eliminated by using a multiple-response test requiring subjects to rank a recognition list consisting of old and new items. Nevertheless recall impaired subsequent recognition in both experiments, the effect being most marked for lowly ranked items. The recognition test in the first experiment was carried out in two stages. This made possible a direct examination of whether recall has an effect on the recognition criterion. No evidence for such an effect was obtained. Other ways in which recall may affect the recognition criterion are discussed.     

Carbon dioxide as a reinforcer in escape conditioning

The effects of varying CO₂ concentration, and intervals between CO₂ presentations, were determined from the performance by five pigeons of a learned motor act which eliminates CO₂ from the inspired air. The length of time from the onset of an externally-produced increase in inspired CO₂ to the performance of the learned motor response terminating the CO₂ presentation was inversely related to the CO₂ concentration presented (3 per cent and 5 per cent) and directly related to the inter-trial interval (3 minutes and 1.5 minutes). Chemoreceptors on the ventrolateral surfaces of the medulla are postulated to be the initial site of stimulation in the chain of events leading to the behavioral bioregulation of inspired CO₂ concentration.     

Some physical determinants of viewing time under three instructional sets

One-hundred fifty human Ss viewed 32 patterns under neutral (N), pleasingness (P), or interestingness (l) instructional sets. An analysis of variance indicated that patterns with larger areas were viewed longer than patterns with smaller areas under all conditions; however, this effect was more pronounced under the P and I conditions than under the N condition. Patterns containing 9-sided shapes were viewed longer than those containing 3-sided shapes under the N and I conditions, while the reverse was true for the P condition.     

Dissociations between procedural and episodic memory: effects of time and aging

The issue of multiple memory systems is explored. Young and older adults (mean ages = 20 and 71, respectively) named pictures and were tested immediately, 1, 7, or 21 days later. Episodic memory (recognition) for pictures was significantly lower in older relative to young adults and declined systematically across all retention intervals in both age groups. In contrast, procedural memory (repetition priming in picture naming) revealed no reliable age differences. In both age groups, priming declined within the first 24 hr, but unlike recognition, there was no further decrement from 1 to 21 days. There were also within-subject dissociations: The magnitude of priming was equivalent for remembered and forgotten items, and the relation between recognition and priming across intervals was nonmonotic, revealing a reversed association. The findings were interpreted within a multiple-memory-systems framework.