In a daily time–place learning task,time is only used as a discriminative stimulus if each daily session is associated with a distinct spatial location

It is difficult for rats to acquire daily time–place (TP) learning tasks. One theory suggests that rats do not use time of day as a stimulus signaling a specific response. In the present study, we tested rats’ ability to use time of day as a discriminative stimulus. A fixed-interval procedure was used in which one lever provided reinforcement on a FI-5-s schedule in morning sessions, and the same lever provided reinforcement on a FI-30-s schedule in afternoon sessions. Because only one place was used in this paradigm, the rats could only use time of day to acquire the task. Mean responses during the first 5 s of the first trial in each session indicated that the rats did not discriminate between the two sessions. In Phase II, a different lever location was used for each of the two daily sessions, which meant that both spatial and temporal information could be used to acquire the task. The rats readily acquired the task in this phase, and probe trials indicated that the rats were using a combination of spatial and temporal information to discriminate between the two different trial types. When the spatial cue was removed in Phase III, rats no longer discriminated the two sessions, suggesting that time can only be used as a discriminative stimulus when each daily session is associated with a distinct spatial location.     

Construction and Validation of an Eight-Iron Approach Test

Abstract

The purpose of this study was to construct a golf test which would be usable for assessing the ability to perform an eight-iron approach shot at a distance of 12 yards from the pin. A good approach shot was defined as one which is high enough to avoid potential hazards between the point of contact and the pin and which comes to rest at or near the pin. Pilot studies were conducted to determine target size, number of trials and days of testing, hitting distance, objectivity, and reliability. The revised test was administered to 424 beginning golfers. Reliability estimates determined by analysis of variance procedures and by correlation techniques indicated that the test was reliable for the subjects involved. Logical validity was claimed and was further supported by comparing mean scores of a beginning and an experienced group. The test confidently differentiated the performance of the two groups.     

E-Book Collection Development: Formalizing a Policy for Smaller Libraries

Three librarians from two similar but unaffiliated state colleges—both members of larger university systems—discuss how they confronted similar e-book acquisition concerns. In this session, presenters described how they took two different approaches toward revising their collection development policies, economizing their processes and streamlining their workflows. The presenters discussed patron-driven acquisition e-book programs, as well as the importance of communication and collaboration among library personnel. By formalizing the purchasing decisions of electronic formats, libraries can provide the structure needed to support changing staff roles and shrinking resources, as well as address important related issues such as accessibility and timeliness.     

Infants' perception of melodies: the role of melodic contour

Infants 8-11 months of age were exposed to repetitions of a 6-tone sequence or melody, then tested for their discrimination of transpositions of that sequence as well as other melodic transformations previously used by Massaro, Kallman, and Kelly with adults. In experiment 1, infants showed evidence of discriminating all transformations from the original melody. In Experiment 2, the task was made more difficult, and infants failed to discriminate transpositions of the original melody as well as transformations that preserved the melodic contour and approximate frequency range of the original melody. By contrast, infants showed evidence of discriminating transformations that violated the contour of the original melody or that included changes in the octaves from which component tones were drawn. This global processing strategy parallels that used by adults with atonal or unfamiliar tonal melodies.     

Rats' performance on an interval time-place task: Increasing sequence complexity

Rats were trained on an interval time-place learning (TPL) task in which the location of food availability depended on the time since the start of the session. Each of four levers (numbered 1, 2, 3, 4) provided food on an intermittent schedule for two nonconsecutive 3-min periods. The order in which the levers provided food was 1, 2, 4, 3, 2, 3, 1, 4. This order was consistent across sessions. Previous research conducted in our lab has shown that when only four “places” are used, rather than the eight in the present study, rats use a timing strategy to track the location of food. Pizzo and Crystal (2004) recently trained rats on an interval TPL in which each of eight arms of a radial arm maze provided food. They found evidence suggesting that rats used both spatial and temporal information. In the present study, in which a revisiting strategy was used (i.e., each lever provided food on more than one occasion), the rats tracked both the spatial and the temporal availability of food for the first half of the session. Interestingly, in the second half of the sessions, the rats appeared to be timing the availability of food even though they did not know where it would occur. That is, the rats knew the temporal, but not the spatial, contingencies for the second half of the session. It appears that the requirement of revisiting a previously reinforced lever resulted in rats' no longer being able to solve the spatial aspect of the task.