Environmental constraints on human memory

During foraging, animal travel appears to be periodic, smooth and regular. However, a closer examination of animal search patterns suggests that foraging displays a fractal pattern known as Lévy flights. Lévy flights or Lévy distributions are positively skewed; heavy-tailed distributions that contain many more extremely large distances than would be expected from a Gaussian distribution and have a slope of (1 < ≤ 3). Although, any number in this range will give rise to a Lévy flight pattern, the closer =2, the more optimal the search. That is, the more efficient the organism’s performance. In animals we know that when prey is scarce, foraging patterns conform to Lévy flight patterns and that when prey is abundant the distribution of intervals no longer follows a power law. For animals, the adaptive benefit of Lévy flights is fewer unsuccessful stopping points that in time maximize foraging performance. In terms of performance this means that the food distribution (environment) informs the movement patterns of the animal. Similarly, in humans there are environmental constraints that influence memory performance. As such, the structure of the environment may also constrain patterns of memory performance. In this study I investigate the possibility that there might be a parallel between animal foraging patterns and human memory performance. To do so, I conducted three experiments, where I manipulated the availability of environmental constraints and observe changes in the scaling exponent. In Experiment one, I replicated the work of Rhodes and Turvey (2007), were it was found that participants’ inter-recall intervals (IRIs; the time-lapse between memories) reproduce a Lévy flight distribution. In Experiment 2, I used the same task, and in addition gave participants a sub-categorical list to guide their memory; I used this list to demonstrate that a rich environment has the potential to change the scaling exponent. In my final experiment, I added a constraint (participants recalled in alphabetical order). I did this, to demonstrate that in a sparse environment, performance is optimized. Results suggest that memory performance follows a Lévy flight pattern. However, I hypothesized a parallel could be drawn across three properties of Lévy flight patterns and I found a parallel across one property only. That is, the environmental manipulations presumed to cause changes in the scaling exponent did not always cause the expected change. Nonetheless, these results are consistent with previous findings of Lévy flight patterns in human memory (Rhodes & Turvey, 2007), thus a conclusion that can be drawn from this work is that a parallel between foraging and human memory exists. What remains to be answered is to what extent can this parallel be drawn.

Name thesis:degree_name

MA

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Arts and Sciences: Psychology

Grantor dc:publisher

University of Cincinnati

Year dc:date

2012

Author dc:creator

• Nash, Bertha

Contributors dc:contributor

• Holden, John

• Psychology
• Memory retrieval
• Levy distribution
• Foraging
• Levy flights
• memory patterns

Statement dc:rights

• unrestricted
• This thesis or dissertation is protected by copyright: all rights reserved. It may not be copied or redistributed beyond the terms of applicable copyright laws.

Language dc:language

English

Repository record dc:identifier

http://rave.ohiolink.edu/etdc/view?acc_num=ucin1353341955

OAI identifier oai:identifier

oai:etd.ohiolink.edu:ucin1353341955