Animal cognition is the mental capacity of animals as well as the study of animals’ mental capacity. The study of mental capacities of animals has stemmed from comparative psychology, which includes studying the conditioning of animals and their learning. Working memory is a major executive function that makes up the cognitive system and deals with information by providing transient holding, processing as well as manipulation. The study of working memory in animals has mainly focused on spatial memory with most of the studies trying to provide a clarification for spatial memory psychological basis together with the hippocampus role.
Balda & Nims (1995) investigated the spatial memory of 4 seed-caching corvid species in relation to their dependence on stored food. The authors assert that these species’ differences are noted in the way they depend on stored food with the spatial memory differences being correlated with a better performance amongst the species that are more cache-dependent. Evidence is provided to indicate that there is no correlation between color task and cache-dependence. Furthermore, there are no significant differences noted in memory testing for this case. The authors provide further evidence in the acquisition and retention of operant spatial non-matching-to-sample tasks. The evidence shows that in spatial tasks, the differences among species are found in their acquisition of information and during retention. The evidence proves that natural history has a significant effect on the evolution of memory among these species. The authors highlight the fact that, natural evolution has acted differently when it comes to the processing of non-spatial and spatial information among the corvid species.
On the other hand, Lind et al. (2014) presents the results of a study they carried out dealing with the meta-analysis of data sets obtained through delayed matching-to-sample (DMTS) studies involving various animals’ species. The test involved presenting a sample stimulus to the subject and then removing it so that after sometime, two or more stimulus are presented to the subject again. This time, the subject is rewarded for selecting the stimulus that matches the sample. As such, the study involved the use of performance versus delay data to find out the two most probable parameters that can be used to characterize the working memory of the animals being studied. In this case, the two parameters that the authors used include the maximum performance that was possible when there was no delay and the performance rate with continuous increase in delay. The results provide evidence that there is no variation between the zero-delay performance amongst all the mammals, birds, and bees studied. The DMTS data analysis presents a variation in memory spans among the animals with spans ranging from seconds to several minutes. The authors go on to provide their suggestion concerning the cases of animals whose memory spans are much longer, that is several days to months. They suggest that such animals have a specialized memory system for dealing with information that is specific and biologically significant for instance food caches. According to the authors, events triggering these systems will be remembered for extended periods while events that do not trigger these systems are forgotten shortly after.
Both articles are related as they center on the issue of working memory among animals and propose that the animals with a food storage function have a better performance in terms of spatial memory. However, the articles differ in terms of species involved as Balda & Nims focus on corvid species while Lind’s article focuses on a wider population involving mammals, birds, and bees. Balda & Nims article presents similar sentiments to those of Lind et al. (2014) especially in the matter of food caches. Both articles agree that animals with a longer memory spans are the cache dependent animals. However, Balda & Nims fails to provide significant reasons for this observation. Lind’s article tries to provide the reason for lengthened memory spans among animals that are cache dependent by suggesting that such animals are used to utilizing some parts of their system for extended periods for instance food storing. When a stimulus is presented to these animals and triggers the part of their system that deals with storage of food, that stimulus is likely to be remembered for a longer time than the other stimulus. A significant difference between the two articles is noted in the idea presented by the Balda & Nims who propose that natural evolution plays a role in the spatial and non-spatial memory of animals. Lind’s article does not highlight such matters and only focuses on the fact that different species will have different memory lengths. The article further highlights that the difference brought by features such as food storage among animals also plays a significant role in the difference in working memory that are noted among the different species of animals. Balda & Nims may have noted the idea of a role played by natural evolution in their article as they involved a significantly lower number of participants and a small data set.
I feel that the study performed by Balda & Nims is not reliable. The data set they used was very small and the fact they never used many species means we cannot generalize the information they obtained. Furthermore, the information was collected many years ago. There is a possibility that accurate data was not collected then as there lacked tools that collect data with precision such as those that exist in the world today. The information they obtained can only be relevant in the context of the corvid species and not among other birds, mammals, or bees. The study by Lind et al. is more reliable and I feel that their conclusion on the idea of a specified body system playing a part in the extended memory spans is true. One of the things that make this conclusion valid is the fact that they used varied species of animals that comprised birds, bees, and mammals. Their data set is large and therefore, the chances of error have been minimized. I choose to side with the idea that animals exhibiting longer memory spans have a specific part in their system that once activated by a certain stimulus, they are not likely to forget it in the near future. The working memory will act whenever called upon especially in the role of information retention. However, in case the information presented does not resonate with parts of the animal system, the information will be easily released, as it appears insignificant in the working memory. However, information that stimulates parts such as the part responsible for food storage will be held by the working memory for longer periods.
I can predict that in the next few years, there is likelihood that many publications concerning animal cognition will come into existence. However, most of these publications will present conflicting information since the field is still fresh and it is obvious that data errors are likely to occur especially since there is little information for guiding those who wish to delve into these studies. Furthermore, the lack of a set of agreed parameters that are used in gauging the working memory of animals means that comparison of different studies will be difficult. I think that delayed versus performance studies should be carried more frequently to confirm the various assumptions that are being brought up. Since the study of animal cognition and more specifically, the working memory, has started just recently, it is paramount that numerous studies are conducted to clear up the air and come up with succinct conclusions.
References
Lind, J., Enquist, M., & Ghirlanda, S. (2014). Animal memory: A review of delayed matching-to-sample data. Behavioural processes, 117, 52-58.
Olson, D. J., Kamil, A. C., Balda, R. P., & Nims, P. J. (1995). Performance of four-seed caching corvid species in operant tests of nonspatial and spatial memory. Journal of Comparative Psychology, 109(2), 173.
