Experiment 2: Context generalization following delayed context shift

Hypothesis 1 It was hypothesized following an immediate delay subjects would be able to discriminate between two contexts  Subjects trained in context A and immediately tested in context B for would not run down the runway as quickly in B as they did in A; whereas subjects trained in context A and tested in context A would show little to no difference in their time to run down a run way

Hypothesis 2 It was hypothesized following an longer delay subjects would generalize the two contexts as indicated by similar performance between the two groups  Subjects trained in context A and tested in context B a week later would run down the runway as quickly in B as they initially did in A suggesting that the subjects generalized the two contexts; similarly subjects trained in context A and tested in context A would show little to no difference in their time to run down a run way

Subjects 16 female Long-Evans rats approximately days old  Subjects were quasi-randomly assigned to one of four groups (n=4 per group)

Apparatus & Materials Both runways had the following dimesions 61” long X 5” wide and the walls 4” high and contained a food cup at the end; food cup contained one fruit loop Context A  Walls were gray  Floor was a wire grid  44” off the floor  Covered with a plexiglass lid  Normal light conditions

Apparatus & Materials Context B  Walls were white  Floor was covered with coarse grit sandpaper  24.5” off floor  No lid on top  Illuminated by three desk lamps  Contained lemon scent throughout

Figure 1a & 1b Context A

Figure 2a & 2b Context B

Procedure The first 3 days of the study were used as pre-testing in order to get the subjects acclimated to context A  Each day every subject was given 5 trials, a trial consisted of the subject starting at one end and running to the other end and ended once the subject began eating the fruit loop  Each subject was given 5 minutes per trial, if the subject failed to perform they would be removed and the next trial would begin Once the subjects reached asymptotic performance all subjects were given one day of testing in context A in order to establish baseline performance  Each subject was given 3 trials

Procedure Following baseline testing subjects were quasi- randomly assigned to one of four groups (n=4 per group)  Each subject was given 3 trials Two groups were either tested in context A or context B two days after baseline testing The other two groups were tested in context A or context B one week after baseline testing

Procedure Initial performance as well as baseline performance was analyzed to determine whether there were any group differences The dependent measure was the difference in time it took to run down the alley from baseline to testing  Averaged across 3 trials  Positive score indicates improved performance; subject running quicker  Negative score indicates that it took longer to reach the end

Initial performance

SourceSum of SquaresdfMean SquareFSig. PreTest PreTest * Context PreTest * Delay PreTest * Context * Delay Error(PreTest) Context Delay Context * Delay Error

Initial performance Pre-Training D1Pre-Training D2Pre-Training D3 Mean2 Days1 Week2 Days1 Week2 Days1 Week Same Different PreD1PreD2PreD3 S.D.2 Days1 Week2 Days1 Week2 Days1 Week Same Different

Initial performance A context X delay X day repeated measures ANOVA demonstrated a significant effect of day F(2,24)=74.29, p.05) This suggests that all subjects were performing similar prior to any experimental manipulation, but were demonstrating improved performance by the final day of pretesting as indicated by a reduced time to reach the end of the alley

Baseline

Source Sum of Squaresdf Mean SquareFSig. Context Delay Context * Delay Error

Baseline Mean2 Days1 Week Same Different S.D.2 Days1 Week Same Different

Baseline A context X delay ANOVA demonstrated no significant differences between any of the groups (p’s >.05) This suggests that during baseline testing there were no significant difference between any of the subjects’ performance

Mean difference from baseline * p<.05

Mean difference from baseline Source Sum of Squaresdf Mean SquareFSig. Context Delay Context * Delay Error

Mean difference from baseline Mean2 days1 Week Same0.5 Different-90.5 S.D.2 days1 Week Same Different

Mean difference from baseline A context X delay ANOVA found a significant main effect for context, F(1,12) = 8.35 and delay F(1,12) = 8.35, as well as a significant context X delay interaction F(1,12) = 15.78, p’s<.05 The significant effect of context indicates that subjects tested in a different context performed significantly poorer, as indicated by a slower running time during testing The significant effect of delay suggests that subjects tested immediately following baseline testing were able to discriminate between the two contexts The significant context X delay interaction suggests that subjects tested in a different context 2 days after baseline are able to discriminate between the two environments whereas subjects tested in the different context 1 week later is generalizing the different context as indicated by similar performance to subjects tested in the same environment as baseline at both 2 days and 1 week

Some extra information There are numerous books and articles about this topic  Generalization and discrimination of context  Recall cues  Contextual learning Remember to discuss this in an overall context, don’t just simply regurgitate try to integrate The challenge in this is to try to relate this to other aspects of the literature or even find conflicting studies  In other words why are our findings important, what can people take from this study

Some extra information An important paper Gisquet-Verrier, P., & Alexinsky, T. (1986). Does contextual change determine long-term forgetting? Animal Learning & Behavior, 14(4), Can use this, but it can’t count towards the two paper min. requirement (but it is very useful)

Some extra information Remember if you need help ask