Biomedical subjects

Lorretto Cunningham

Publications and source records attributed to Lorretto Cunningham.

3 recordsLinked to original sources

PubMed2005

Long-term retention and overshadowing of proximal and distal cues following habituation in an object exploration task.

The object displacement task is a popular tool used to investigate spatial learning and memory. However, little attention has previously been given to long-term retention of spatial information following habituation to this task. Furthermore, the role of both proximal and distal cues in this type of passive retention of spatial information is controversial. In Study 1, we examined habituation in the object displacement task across 4 days and examined reactivity to spatial change 7 days post-acquisition. We found that rats habituated rapidly to the environment and retained this environment for the 7 days. Furthermore, this experiment shows that both proximal and distal spatial cues are important in the encoding of the environment during object displacement learning task. In Study 2, we examined the effect of overshadowing and demonstrate that proximal visual spatial cues can overshadow distal spatial cues if a conflict arises between both set.

Animals↗

PubMed2004

Retention of cue-based associations in the water maze is time-dependent and sensitive to disruption by rotating the starting position.

Research has focused mainly on the acquisition phase of spatial tasks, while retention has been relatively ignored. In three experiments, we determine the type of information that is retained in spatial memory using the water maze task. In experiment 1, we demonstrate that by rotating the distal cues 180 degrees post-acquisition Wistar rats search in the opposite area to where the platform should be. This search continues for a maximum of 30 s. We then demonstrate (experiment 2) that by rotating the starting position (180 degrees post-acquisition) animals remain at the starting-point for 10 s. They then commence searching in the platform area. In experiment 3, we demonstrate that rotations of distal cues and starting position post-acquisition impair retention of the platform's location. We suggest that the association between the configuration of distal cues and platform location is retained in memory but the association is fragile and sensitive to disruption.

Analysis of Variance↗

PubMed2003

Massed but not spaced training impairs spatial memory.

The Morris water maze and the object displacement task are two popular tools used to investigate spatial learning and memory. Research has focused mainly on the acquisition of spatial tasks while little attention has been given to the retention phase. We examined the effects of different training procedures on retention of the water maze and also reactivity to spatial change in the object displacement task 7 days post-acquisition. We found that massed-trained animals were impaired on retention of the water maze compared to those animals that had received spaced-training. We also found that the massed-trained animals habituated readily to their environment in the object displacement task while the spaced-trained group did not. Furthermore the massed-trained group did not react to spatial change 7 days post-habituation compared to the increased reactivity displayed by the spaced-trained group. Results are discussed in terms of poor encoding of the environment leading to poor retention.

Analysis of Variance↗