Exp FInal Paper

THE EFFECT OF HOUSING CONDITIONS ON BARNES MAZE PERFORMANCE IN SPRAGUE-DAWLEY RATS

The Effect of Housing Conditions on Barnes Maze Performance in Sprague-Dawley Rats

Anthony DeFilippo

Partners: Christina Lin, Meghan Gallo, Maeve Robertson

Providence College

1

THE EFFECT OF HOUSING CONDITION ON SPATIAL MEMORY IN RATS

Abstract

The Barnes maze is used to assess spatial memory primarily in rodents. Previous

literature has established behavioral differences due to housing conditions. The purpose of this

study was to determine whether or not differential housing conditions, individually- versus

socially housed, in male Sprague-Dawley rats has an effect on spatial memory, which was

measured using the Barnes maze. A total of 20 male Sprague-Dawley rats were used, each of

which underwent two trials a day for three days in addition to two probe trials to assess long-

term memory. Barnes maze performance was measured in total latency (s) and total distance

traveled (cm) to the escape box. For both these measures, there was a main effect for time, but

no main effect for housing condition and no interaction between the two. Thus, there was no

significant effect of housing condition on Barnes maze performance. This could have been due

to how individually housed was defined in this experiment, the daily handling of the rats, and the

small sample size. This study could potentially serve as a foundation for exploring the effects of

housing condition on spatial and long-term memory via the Barnes maze.

2


Introduction

Spatial memory is referred to as the ability to recall particular spatial locations

using stimuli for discrimination learning when there are distinctive external stimuli present in the

environment. This is also referred to as “place learning” and if one is able to use place learning

in order to solve a discrimination problem, then that subject is said to have learned rapidly and

has good spatial memory (Olton et al., 1976). In rodent studies, it has been demonstrated that

spatial memory is controlled by the hippocampus and is thought to be localized to the CA3

region of the hippocampus. The neuronal progenitor cells in the subgranular zone of the

hippocampus are very important for spatial memory because as they proliferate, travel, and

differentiate into granular cells, they begin to form synaptic connections with parts of the CA3

region (Williams et al., 2001). The Barnes maze directly measures rats’ spatial memory. In the

Barnes maze, latency to reach the goal box and/or distance traveled therefore indicate the ability

of the rat to use the particular configuration of distal visual cues to learn and remember the exact

location of a target or goal zone (Harrison et al., 2009). A great deal of previous studies have

directly looked at the relationship between stress and spatial memory, ultimately concluding that

stress, through the action of the stress hormone, corticosterone, impairs spatial memory and

causes hippocampal impairment in rodents (McLay et al., 1998). Also, it has been demonstrated

that housing condition affects the ways in which rats react to exposure to chronic stress

(Westenbroek et al., 2003). However, there have not been many studies aimed primarily at

studying the effect, if any, of housing condition on spatial memory.

Previous literature has established the glucocorticoid hypothesis: elevated levels of

glucocorticoids levels result in impairment and accelerated aging of the hippocampus.

(Sapolosky et al.,) The hippocampus, in particular the CA3 region, is activated during spatial

3


memory tasks such as the Barnes maze and Morris water maze. As animals age, the plasticity

and proliferation of hippocampal cells declines, thus leading to a reduced capability in spatial

memory. Localization of spatial memory in the hippocampus was confirmed in behavioral

studies in which hippocampal impairment in rats was directly correlated with poorer

performance on the Barnes maze. Hippocampal impairment was achieved by exposing rats to 3

months of stress-equivalent concentrations of glucocorticoids, primarily corticosterone (Williams

et al). These corticosterone-induced rats exhibited significantly impaired spatial memory, which

was evident on the Barnes maze, compared to control rats, thus illustrating the hippocampus’s

role in spatial memory (Williams et al). This glucocorticoid hypothesis for hippocampal

functioning was also tested in a more naturalistic setting in which the researchers directly

measured spatial memory using a Y-maze after exposure to chronic stress. Chronic stress in the

rats was induced using two restrainers for 6 hours/day for 21 days after which they tested the rats

on the Y-maze, which is a measure of a rat’s willingness to explore new environments.

Compared to the control group, the rats exposed to the chronic stress resulted in deficits in Y-

maze performance (Conrad et al., 2003). Even though these studies were useful in locating the

part of the brain spatial memory is controlled by and how stress affects it, they didn’t specifically

address how differential-housing conditions could have an effect on spatial memory.

It has also been demonstrated that social isolation has an effect on overall memory and

executive functioning in rats. Using two models of cognition: the novel object recognition

(NOR) task and an attentional set-shifting task, the researchers found that housing condition had

a significant effect on performance on these tasks (McLean et al, 2010). The NOR task is a

measure of episodic and recognition memory while the attentional set-shifting task is a measure

of overall executive function of the rat brain. Compared to rats socially housed, socially isolated

4


rats showed a significant decrease in performance on both tasks. These results confirm that some

cognitive functions, primarily memory, in rats are impaired due to social isolation (McLean et al,

2010). However, housing conditions can have an effect on ways of dealing with, or coping, with

mild stress. Social housing of rats has been found to provide some protection against the

negative consequences of both mild and chronic stress. In a study by Baker & Bielajew, the

researchers measured the effects of stress using a sucrose preference test, a social interaction test,

and rate of weight gain. Compared to the socially-housed rats, the individually housed rats

exposed to the stressor had significantly lower sucrose consumption and reduced weight gain,

showing that lack of social interaction may make individuals more prone to stress-related

diseases (Baker & Bielajew, 2007). However, there is little previous literature about the effects

of housing conditions on spatial memory alone. Thus, the purpose of this study was to determine

whether or not differential housing conditions, individually- versus socially-housed, in male rats

has an effect on spatial memory, which was measured using the Barnes maze.

This study aimed to examine the effect of differential housing conditions alone on spatial

memory in rats using the Barnes maze. While the Barnes maze is a mildly aversive test, the only

stress that causes any motivation to find the escape hole is the bright lighting in the testing room.

This causes a very small increase in corticosterone levels, which are not significant enough to

alter hippocampal function (McLay et al). Long-term memory was also assessed via probe trials

after all experimental trials were completed for both groups. The hypotheses tested were that

there would be a significant effect of differential housing condition on spatial memory and long-

term memory, evident by a significant difference in learning curves for the two groups.

5


Materials and Methods

Subjects

Twenty male Sprague-Dawley rats weaned at postnatal day 21 from different litters were

obtained from Charles River at postnatal day 26. After arrival, rats were randomly divided into

two groups, socially and individually housed animals. Socially housed animals were housed in

two groups of five in transparent (46.5x36.5x20.5 cm) cages (n=10). Individually housed

animals were housed in transparent (43x22x21 cm) cages (n=10). All animals were kept in the

same colony room in the vivarium at Providence College. Animals were maintained on a 12-

hour light/12-hour dark cycle and provided with food and water ad libitum. Room temperature

was maintained at (insert degrees). All animals were handled for approximately two minutes

each day six weeks prior to experimentation and throughout the experiment. All handling of rats

took place during the time frame of 3:30 PM to 6:00 PM. A strict feeding and handling schedule

was used to ensure that all animals received approximately the same amount of handling and to

control for experimenter differences in handling. This also ensured that there would be no stress-

related differences in cell loss and cognitive function (Williams et al., 2001). Cleaning of the

cages and weighing of the rats took place on every Tuesday throughout the duration of the

experiment. All cages contained enriched bedding. All procedures were approved by the

Providence College Institutional Animal Care and Use Committee and in accordance with the

NIH Guide for the Care and Use of Laboratory Animals.

Apparatus

The Barnes maze consisted of a black contact paper covered circular disk (diameter) with

18 equally spaced holes along the perimeter (Barnes et al., 1980). The maze was elevated 133

cm off of the ground to ensure that rats did not spontaneously jump from the maze platform to

6


the ground (Mclay et al., 1998). Each hole was open with nothing underneath except for the

chosen, discrete escape hole. A black acrylic escape box 37.5 cm x11.5 cm was placed

underneath the escape hole. The escape box was 5.5 cm deep with a step 4.5 cm high and 6 cm

wide on the inside of the box. The escape hole remained in a fixed position relative to the room

throughout the duration of testing (Mclay et al., 1998). Two white boards, each six feet in

height, were placed across from each other an equal distance from the Barnes maze. One board

contained the visual cue of a red triangle, and the other contained a visual cue of a brown ‘X’. In

addition to the ceiling lighting, two flood lights of 150 watts each were placed on top of each

whiteboard for more motivation (Williams et al., 2003; Harrison et al., 2006). All other visual

cues in the room (researchers, chairs, tables etc.) remained in the same configuration throughout

the entire span of testing because the rats rely on these cues as reference points for locating the

escape hole (Sunyer et al., 2007). A camera configured to Ethovision was placed directly over

the center of the Barnes maze for automated video recording and behavior scoring.

Procedure

All 20 rats, within each set of 5 rats, were to assigned a random testing order with the

assistance of a sequence generator. Prior to the trial, animal cages were moved to a waiting area

outside of the testing room where they were place in the start chamber. Each trial began with the

circular, opaque, black start box placed in the center of the maze with an animal placed inside.

The circular start box, 26.5 cm diameter, ensured a random starting orientation of the rat at the

beginning of the trial. All animals were handled and placed in the center of the maze by one of

two female researchers in order to control for an experimenter confounding variable and prevent

additional stress. The door of the testing room was closed during trials to prevent possible

escape of animals and block out extraneous noise. The animal acclimated to the start box in the

7


center of the maze for 10 seconds before the commencement of each trial (Sunyer et al., 2007).

In the event that an animal fell off of the maze, they were promptly place back on the maze in the

place they fell off. Following each trial, bolus was collected and counted. The start chamber,

maze and escape box were cleaned down with a 70% alcohol solution. Individually housed rats

were placed back into original housing cage and returned to vivarium while socially housed rats

were placed in a separate, temporary group housing cage until all 5 rats completed testing. They

were then placed back into original housing cage together and returned to the colony room.

Experimental Trials. Each animal underwent two trials with an intertrial interval of about

120 minutes each day over the course of three days. On each trial, 17 of the 18 holes were

empty and the remaining escape hole provided entry into the escape box. After the 10-second

acclimation period, the start box was lifted and researchers started the Ethovision experimental

recording. Ethovision recorded animals using dynamic subtraction in Ethovision. Animals

explored the maze freely for 210 seconds or until they entered the escape box, upon which the

Ethovision recording was stopped. When the animal found the escape box, the floodlights were

promptly turned off and the rat was allowed to remain in the escape box for 20 seconds before

being removed and returned to appropriate cage (Williams et al., 2003). If rats did not enter the

escape box after 210 seconds, they were promptly placed into the escape box. The lights were

immediately turned off and the animal acclaimed to the escape box for 20 seconds in order to

provide negative reinforcement (Sunyer et al., 2007).

Probe Trials. Two probe trials were performed in which the escape box was removed

from underneath the escape hole. For each probe trial day there was only one trial performed

per rat. Each probe trial lasted 105 seconds, half the time of the experimental trials (Sunyer et

al., 2007). The flood lights remained on for the entire duration of the probe trial. The first probe

8


trial took place on the fourth day of testing to assess spatial memory. Ten days after probe trial

one, a second probe trial took place to observe long-term memory (O’Leary & Brown, 2012).

Data Collection. Total distance traveled (cm) on the maze were recorded via Ethovision.

Latency (s) to escape box was also recorded via Ethovision from the center of the rat’s body.

The number of target visits and entries into the wrong hole were recorded from the rat’s nose via

Ethovision. Number of bolus and if the rat jumped off the Barnes maze during testing was

recorded. Latency, distance traveled and bolus collection were all separately compared with a

mixed ANOVA.

Results

It was hypothesized that housing conditions would have a significant effect on rats’

spatial and long-term memory, as measured on the Barnes maze. Repeated-measures ANOVAs

were used analyze the results, looking more specifically at total distance traveled (cm) and total

latency (sec) to escape box. A P value of .05 was used and the Greenhouse-Geisser correction

was used when the sphericity assumption was violated. Outlier filtering was used to determine

outliers, defined at +/- 2 standard deviations from the mean, and changed to the highest point,

within +/- 2 standard deviations of the mean, plus 1.

Descriptive statistics were performed for the 20 subjects’ performance on the Barnes

maze, measured in total distance traveled (cm) to reach the escape box for each of the three days

and two probe trials. The mean distance traveled (cm) for the individually housed rats was not

significantly different compared to the socially housed rats; the individually housed rats had a

mean distance of 988.70 cm (sd = 628.75) and the socially housed rats had a mean distance of

1422.50 cm (sd = 695.34).

9


Repeated-measures ANOVA was calculated comparing the total distance traveled (cm) to

the escape box of the subjects between-groups at 8 different times: day 1 trial 1, day 1 trial 2, day

2 trial 2, day 3 trial 1, day 3 trial 2, probe 1, and probe 2. There was a main effect for time

(F(1.84,33.2) = 4.066, P = 0.029), no main effect for housing (F(1.84,33.2) = 0.845, P = 0.368), and no

significant interaction between the two variables (F(1.84,33.2) = 1.233, P = 0.302) (Table 1;

Appendix A). This indicates that between trials, all the rats had traveled a significantly greater

distance to the escape box. Housing condition did not have a significant effect on total distance

traveled (cm) to the escape box. However, the mean distance traveled by the individually housed

rats tended to be less than the mean distance traveled by the socially housed rats (Figure 1).

Table 1: F and P values for between-subjects differences on distance traveledFigure 1: Distance traveled (cm) during acquisition trials for individually and socially housed rats

Distance traveled (cm) to the escape hole for probe trial 1 and probe trial 2 was not significantly

different for socially and individually housed rats. There was no main effect for time (F(1,18) =

1 2 3 4 5 60.00

500.00

1000.00

1500.00

2000.00

2500.00

Individually Housed

Socially Housed

Aquisition Trial

Dis

tan

ce (

cm)

10

Variable for repeated measures ANOVA F value P value

Time 4.066 0.029

Housing 0.845 0.368

Time*housing 1.233 0.302


0.770, P = 0.392), no main effect for housing (F(1,18) = 0.00, P = 0.983), and no significant

interaction between the two variables (F(1,18) = 1.472, P = 0.241). Socially housed traveled less

distance and individually housed rats traveled more distance on the Barnes maze from probe trial

1 to probe trial 2 (Figure 2, Appendix B).

Figure 2: Distance traveled (cm) during probe trials for individually and socially housed rats

Follow up independent-samples t tests were run to compare the mean scores between-

groups on day 3 trial 1, day 3 trial 2, probe 1, and probe 2. No significant difference was found

between the means of the two groups for day 3 trial 1 (t(18) = -1.396, p = 0.180), for day 3 trial 2

(t(18) = -1.030 p = 0.317), for probe 1 (t(18) = -1.392, p = 0.0181) or for probe 2 (t(18) = 0.765, p =

0.454).

Descriptive statistics were performed for the 20 subjects’ performance on the Barnes

maze, measured in total latency (s) to reach the escape box for each of the three days and two

probe trials. The mean total latency (s) for the individually housed rats was not significantly

1 20.00

50.00

100.00

150.00

200.00

250.00

Individually Housed

Socially Housed

Probe Trial

Dis

tan

ce (

cm)

11


different compared to the socially housed rats; the individually housed rats had a mean time of

30.50 s (sd = 14.32) and the socially housed rats had a mean time of 33.34 s (sd = 13.88).

A repeated-measures ANOVA was calculated comparing the total latency (s) to the

escape box of the subjects between-groups. There was a main effect for time (F(3.438, 61.891) =

6.615, p = 0.00), no main effect for housing (F(3.438, 61.891) = 0.719, p = 0.407), and no significant

interaction between the two variables (F(3.438, 61.891) = 0.142, p = 0.951) (Table 2; Appendix B).

However, the mean total latency of the individually housed rats tended to be less than the mean

total latency of the socially housed rats (Figure 3). This indicates that between trials, all the rats

had a significantly lower latency to the escape box and housing condition did not have a

significant effect on total latency to the escape box.

Table 2: F and P values for between-subjects differences on latency

Figure 3: Total latency (s) during acquisition trials for socially and individually housed rats

1 2 3 4 5 60.00

20.00

40.00

60.00

80.00

100.00

120.00

140.00

Individually Housed

Socially Housed

Aquisition Trial

Late

ncy

(s)

12

Variable of repeated measures ANOVA F value P value

Time 6.615 0.00

Housing 0.719 0.407

Time*housing 0.142 0.951


Latency to the escape hole for probe trial 1 and probe trial 2 was not significantly different for

socially and individually housed rats. There was no main effect for time (F(1,18) = 1.253, P =

0.278), no main effect for housing (F(1,18) = 0.053, P = 0.820), and no significant interaction

between the two variables (F(1,18) = 2.823, P = 0.110). It took socially housed rats less time, and

individually housed rats more time to find the escape hole from probe trial 1 to probe trial 2

(Figure 4, Appendix D).

Figure 4: Total latency (s) during probe trials for socially and individually housed rats

Follow up independent-samples t tests were run to compare the mean scores between-

groups on day 3 trial 1, day 3 trial 2, probe 1, and probe 2. No significant difference was found

between the means of the two groups for day 3 trial 1 (t(18) = -1.057, p = 0.305), for day 3 trial 2

(t(18) = -0.028, p = 0.978), for probe 1 (t(18) = -1.960, p = 0.066) or for probe 2 (t(18) = 0.851, p =

0.406).

Discussion

Based on the results, we found no significant effect of housing condition, individually

versus socially housed, on spatial memory and long-term memory, which were measured using

the Barnes maze. With regard to total distance traveled, all the rats had a significantly greater

1 20.00

5.00

10.00

15.00

20.00

25.00

30.00

Individually Housed

Socially Housed

Probe Trial

Late

ncy

(s)

13


distance traveled to the escape box between trials for the 6 experimental trials but housing

condition did not have a significant effect on total distance to the escape box. The increases in

distance were due to an increased exploratory activity in the later experimental and probe trials.

There was no significant effect of housing condition on distance traveled in the probe trials,

showing no significant difference in long-term memory. The mean distance traveled by the

individually housed rats tended to be less than the mean distance traveled by the socially housed

rats. With regard to total latency, all the rats had a significantly lower latency to the escape box

between trials and housing condition did not have a significant effect on total latency to the

escape box. There was no significant effect of housing condition on latency in the probe trials

either, showing no significant difference in long-term memory.

Thus, we failed to accept our hypothesis that housing condition would have a significant

effect on these types of memory. However, there was a main effect for time for both total

distance traveled (cm) and total latency (s) for both the individually and socially housed rats,

showing that the rats did learn and acquire spatial memory on the Barnes maze task. There was a

learning curve with regard to the latency of the rat to the escape box, as evident with the decrease

in latency between trials (Figure 3). This can be explained physiologically through synaptic

changes in the brain such as long-term potentiation (LTP) and depression (LDP). Acute

stressors, such as the bright lights and open space used in the Barnes maze task, cause changes at

the NMDA receptors in the CA1 and CA3 region of the hippocampus allowing for a lowered

threshold for LTP. As a result of these physiological changes, a memory is formed through

learning, contributing to an overall change in synaptic plasticity in the rats’ brains (Howland et

al., 2008).

14


One of the main limitations of our study was the housing conditions; the individually

housed and socially housed rats were all housed in the same colony room. The individually

housed rats were housed in transparent cages in which the rats could see, hear, and smell the

other rats present in the room. This took away from the individually housed aspect of our

experiment. Previous literature has established that social isolation, which is defined as

complete restriction from any interaction with another, has a significant effect on behavior,

especially when the rats are exposed to social isolation early in life. Had our individually housed

rats been more socially isolated, this could have resulted in more profound differences in

behavior and ultimately on performance on the Barnes maze (Lukkes et al., 2008). The rats were

also handled six days a week for the duration of the experiment, which could have decreased the

rats’ anxiety and fear responses and could have been another reason why there were not a

significant effect of housing condition on Barnes maze performance. Another major limitation

of our study was the motivators used, which were only two 150 watt floodlights in addition to the

ceiling lights. These lights may not have been strong enough of a stimulus in order to motivate

the rat to find the escape hole and enter the escape box. It has been established that chronic

stress, like a foot shock, has an effect on neurogenesis and general physiological conditions via

the HPA axis. Also, housing conditions play a role in a rat’s ability to cope with stress; social

housing provides a social support structures that helps the rat to better deal with the stressor

present (Westenbroek et al., 2004) Had we used a more chronic stressor as opposed to the acute

stressor of the bright lights and open space, there could have been a more significant effect of

housing conditions on Barnes maze performance.

Based on the results obtained, the primary focus of future directions should be to analyze

search strategies on the Barnes maze. Previous literature has established three different types of

15


search strategies exhibited by rodents on the Barnes maze: random, serial, and spatial strategies.

The spatial strategies, which are based on the visuo-spatial cues positioned around the Barnes

maze, were also present in our experimental setup. Despite there not being a significant effect

of housing condition on spatial memory using the Barnes maze in our experiment, the analysis of

search strategies could have shed light onto why these results were not significant and help

explain differences in behavior (O’Leary et al., 2010). Primary latency and primary distance

traveled to the escape hole should also be included in future studies in order to better determine

if there is a significant effect of housing condition on spatial and long-term memory. Also, a

larger sample size should be implemented to increase the power of the study, since we were

limited to a sample size of 20 rats. However, this study could be a starting point for exploring

the effects of housing condition on spatial and long-term memory via the Barnes maze.

16


References

Baker, S., & Bielajew, C. (2007). Influence of housing on the consequences of chronic mild

stress in female rats. Stress: The International Journal On The Biology Of Stress, 10(3),

283-293.

Barnes, C. A. Nadel, L. Honig, Werner K. (1980). Spatial memory deficit in senescent rats.

Canadian Journal of Psychology/Revue canadienne de psychologie, 4(1): 29-39

Conrad, C., Grote, K., Hobbs, R., Ferayorni, A. (2003). Sex differences in spatial and non-spatial

Y-maze performance after chronic stress. Neurobiology of Learning and Memory, 79: 32-

40.

Harrison, F., Hosseini, A., & McDonald, M. (2009). Endogenous anxiety and stress responses in

water maze and barnes maze spatial memory tasks. Behavioral Brain Research, 198(1),

247-251.

Harrison, F., Reiserer, R., Tomarken, A. McDonald, M. (2006). Spatial and nonspatial escape

strategies in the Barnes maze. Learning Memory, 12: 809-819.

Howland, J. G., Wang, Y. T. (2008). Synaptic plasticity in learning and memory: stress effects

in the hippocampus. Progress in Brain Research, 169: 145-158.

Lukkes, J., Mokin, M., Scholl, J., & Forster, G. (2008). Adult rats exposed to early-life social

isolation exhibit increases anxiety and conditioned fear behavior, and altered hormonal

stress responses. Hormones and Behavior, 55(1), 248-256.

Mclay, R., Freeman, S., Zadina, J. (1998). Chronic Corticosterone Impairs Memory Performance

in the Barnes Maze. Physiology & Behavior, 63(5): 933-937.

17


McLean, S., Grayson, B., Harris, M., Protheroe, C., Woolley, M., & Neill, J. (2010). Isolation

rearing impairs novel object recognition and attentional set shifting performance in

female rats. Journal of Psychopharmacology, 24(1), 57-63.

O’Leary, T. & Brown R. (2012) The effects of apparatus design and test procedure on learning

and memory performance of C57BL/6J mice on the Barnes Maze. Journal of

Neuroscience Methods, 203: 315-324.

Olton, D. & Samuelson, R. (1976). Remembrance of places passed: Spatial memory in

rats Journal of Experimental Psychology: Animal Behavior Processes, 2(2), 97-116.

Sapolsky, R., Krey, L., & McEwen, B. (1985). Prolonged glucocorticoid exposure reduces

hippocampal neuron number: Implications in aging. Journal of Neuroscience, 5(5), 1222-

1227.

Sunyer, B., Patil, S., Hoger, H., Lubec, G. (2007) Barnes maze, a useful task to assess spatial

reference memory in the mice. Nature: Protocol Exchange: 1-13.

Westenbroek, C., Den Boer, J., Veenhuis, M., Horst, G. (2004). Chronic stress and social

housing differentially affect neurogenesis in male and female rats. Brain Research

Bulletin, 64: 303-308.

Williams, B., Luo, Y., Ward, C., Redd, K., Gibson, R., Kuszaj, S., McCoy, J. (2001)

Environmental enrichment: Effects on spatial memory and hippocampal CREB

immunoreactivity. Physiology & Behavior, 73: 649-658.

18


Appendices

Appendix A: Repeated measures ANOVA for distance traveled of individually and socially housed

Tests of Within-Subjects Effects

Measure: DISTANCE_TRAVELED

Source

Type III Sum

of Squares df

Mean

Square F Sig.

Partial

Eta

Square

d

Noncent.

Paramet

er

Observed

Powera

time Sphericity

Assumed

33717638.90

85

6743527.78

2

4.06

6

.00

2.184 20.328 .942

Greenhouse-

Geisser

33717638.90

81.844

18287186.2

47

4.06

6

.02

9.184 7.496 .660

Huynh-Feldt 33717638.90

82.159

15619742.0

66

4.06

6

.02

2.184 8.776 .711

Lower-bound 33717638.90

81.000

33717638.9

08

4.06

6

.05

9.184 4.066 .480

time *

Housing

Sphericity

Assumed

10223050.82

45

2044610.16

5

1.23

3

.30

0.064 6.163 .419

Greenhouse-

Geisser

10223050.82

41.844

5544600.40

8

1.23

3

.30

2.064 2.273 .241


42.159

4735842.19

3

1.23

3

.30

5.064 2.661 .261


41.000

10223050.8

24

1.23

3

.28

1.064 1.233 .183

Error(tim

e)

Sphericity

Assumed

149278384.7

8290

1658648.72

0

Greenhouse-

Geisser

149278384.7

82

33.18

8

4497945.14

7


82

38.85

6

3841856.37

3


82

18.00

0

8293243.59

9

a. Computed using alpha = .05

19


Tests of Between-Subjects Effects

Measure: DISTANCE_TRAVELED

Transformed Variable: Average

Source

Type III Sum

of Squares df Mean Square F Sig.

Partial Eta

Squared

Noncent.

Parameter Observed Powera

Intercept 174415489.4

941

174415489.4

94

26.37

2.000 .594 26.372 .998

Housing 5645634.011 1 5645634.011 .854 .368 .045 .854 .141

Error 119046206.3

8618 6613678.133


20


Appendix B: Repeated measures ANOVA for distance (cm) for probe trials


Measure: DISTANCE

Source

Type III

Sum of

Squares df

Mean

Square F Sig.

Partial

Eta

Squared

Noncent.

Paramet

er

Observed

Powera

time Sphericity

Assumed

24622.74

41

24622.7

44.770 .392 .041 .770 .132

Greenhouse-

Geisser

24622.74

41.000

24622.7

44.770 .392 .041 .770 .132


41.000

24622.7

44.770 .392 .041 .770 .132


41.000

24622.7

44.770 .392 .041 .770 .132

time *

Housing

Sphericity

Assumed

47058.22

81

47058.2

281.472 .241 .076 1.472 .210

Greenhouse-

Geisser

47058.22

81.000

47058.2

281.472 .241 .076 1.472 .210


81.000

47058.2

281.472 .241 .076 1.472 .210


81.000

47058.2

281.472 .241 .076 1.472 .210

Error(time) Sphericity

Assumed

575482.3

8818

31971.2

44

Greenhouse-

Geisser

575482.3

88

18.00

0

31971.2

44


88

18.00

0

31971.2

44


88

18.00

0

31971.2

44



Measure: DISTANCE


21


Source

Type III Sum of

Squares df

Mean

Square F Sig.

Partial Eta

Squared

Noncent.


Intercept1256976.969 1

1256976.9

69

59.19

5

.00

0.767 59.195 1.000

Housing10.229 1 10.229 .000

.98

3.000 .000 .050

Error382219.888

1

821234.438


Appendix C: Repeated measures ANOVA for total latency of individually and socially housed


Measure: LATENCY

Source

Type III

Sum of

Squares df

Mean

Square F Sig.

Partial

Eta

Squared

Noncent.

Paramet

er

Observed

Powera

time Sphericity Assumed 19628.61

15

3925.72

26.615 .000 .269 33.074 .997

Greenhouse-Geisser 19628.61

13.438

5708.63

96.615 .000 .269 22.745 .978


14.585

4280.84

66.615 .000 .269 30.331 .994


11.000

19628.6

116.615 .019 .269 6.615 .682

time *

Housing

Sphericity Assumed 422.678 5 84.536 .142 .982 .008 .712 .081

Greenhouse-Geisser 422.678 3.438 122.928 .142 .951 .008 .490 .076

Huynh-Feldt 422.678 4.585 92.183 .142 .976 .008 .653 .080

Lower-bound 422.678 1.000 422.678 .142 .710 .008 .142 .065

Error(time

)

Sphericity Assumed 53412.22

590 593.469

Greenhouse-Geisser 53412.22

5

61.89

1

863.001

22



5

82.53

4647.155


5

18.00

0

2967.34

6



Measure: LATENCY


Source

Type III

Sum of

Squares df

Mean

Square F Sig.

Partial Eta

Squared

Noncent.


Intercept 121539.67

51

121539.67

5

412.94

5.000 .958 412.945 1.000

Housing 211.736 1 211.736 .719 .407 .038 .719 .127

Error 5297.835 18 294.324


23


Appendix D: Repeated measures ANOVA for latency (s) for probe trials


Measure: MEASURE_1

Source

Type III

Sum of

Squares df

Mean

Square F Sig.

Partial

Eta

Squared

Noncent.

Paramet

er

Observed

Powera

time Sphericity Assumed 471.969 1 471.969 1.253 .278 .065 1.253 .185

Greenhouse-

Geisser471.969 1.000 471.969 1.253 .278 .065 1.253 .185

Huynh-Feldt 471.969 1.000 471.969 1.253 .278 .065 1.253 .185

Lower-bound 471.969 1.000 471.969 1.253 .278 .065 1.253 .185

time *

Housing

Sphericity Assumed 1062.96

11

1062.96

12.823 .110 .136 2.823 .356

Greenhouse-

Geisser

1062.96

11.000

1062.96

12.823 .110 .136 2.823 .356

Huynh-Feldt 1062.96

11.000

1062.96

12.823 .110 .136 2.823 .356

Lower-bound 1062.96

11.000

1062.96

12.823 .110 .136 2.823 .356

Error(time) Sphericity Assumed 6777.93

018 376.552

Greenhouse-

Geisser

6777.93

0

18.00

0376.552

Huynh-Feldt 6777.93

0

18.00

0376.552

Lower-bound 6777.93

0

18.00

0376.552



Measure: MEASURE_1


Source

Type III

Sum of

Squares df

Mean

Square F Sig.

Partial Eta

Squared

Noncent.


Intercept 14402.025 1 14402.025 40.790 .000 .694 40.790 1.000

24


Housing 18.769 1 18.769 .053 .820 .003 .053 .055

Error 6355.346 18 353.075


25

Documents

Exp FInal Paper