Contents
Abstract 2
Introduction 3
Method 4 Participants 4 Equipment 4 Stimuli 5 Procedure 5
Results 6
Discussion 7
Conclusion 8
References 9

Abstract

Studies on memory span have gained prominence over the years as specialists explore how the human brain stores information. This report shall give details of an experimental research that was designed to explore whether the length and type of stimuli affects one’s ability to recall items within a short period of time. The items used to carry out the research shall be highlighted and the research findings analyzed. A discussion on whether there length and type of stimuli relate to our recall accuracy shall also be provided in order to establish whether findings on previous research were conclusive.

Introduction

The study of the human brain functions has been in existence for many years. As a result, psychologists and behavioral scientists have over the years developed various theories such as Piaget’s stages of cognitive development, which aim at explaining how the brain works in regard to how it receives, processes and stores information during various stages of development (Zastrow & Kirst-Ashman, 2009, p.111). These theories have been directed by research conducted on various branches of psychology. Of particular interest is cognitive psychology, which can be defined as a branch of psychology that studies mental processes that facilitate learning, remembering, thinking and perception among other processes (Brown, 2006, p. 6). Previous studies on the different types of memories indicate that various parts of the brains have the ability to store different memories. This is further supported by a number of cognitive theories that discuss the presence of short term memory stores, which temporarily holds information before it is processed into long term memories. Despite the progress made in determining how these memory stores works, little has been done to establish the capacity of information the human mind can remember or recognize within a short period of time. Previous studies have indicated that the short term memory can hold information limited to seven (+/-two) items within a short period of time. To improve on these findings, this research shall modify previous memory span experiments in order to explore whether the findings change when different items (numbers and words) are used. As such, this study explores whether the mind processes digits and words the same, whether the capacity to hold information will be similar for words and digits having different lengths. It is expected that participants will easily remember more two digit numbers as compared to four digit numbers. The same is expected for short words in comparison to long words. It is also hypothesized that participants will recognize more long words than they will, long numbers.

Method

Participants

The participants of this experiment consisted of 15 students who pursue various courses at the selected learning institutions. The participants were requested to volunteer through an e-mail sent to the selected students. They were duly informed that their participation was not a requirement of any class and that they could not receive any credit for their participation. The sample group consisted of six females and nine male participants. In regard to age, the selected participants were aged between 18 and 25 years old and they represented selected grade levels as ha been illustrated below.
Table 1: Classification of participants
|Grade level of participants |No. of participants |Gender of participants |
|Freshman |Three |Two female, One male |
|Sophomore |Four |Two female, One male |
|Junior |Three |One female, Two male |
|Senior |Five |One female, Four male |
|Total |15 |15 |

Equipment

The equipment used to conduct the experiment included consisted of a computer and a monitor. The computer was a HP brand with a Pentium 4 processor. The monitor was of the same brand and had a 19 inches LCD display screen. The screen resolution was set at 1024 x 768 pixels. The experiment screen is 360mm x 200mm with a grey background. Papers and pencils were used to collect results of the demographical information provided by each participant.

Stimuli

The two independent variables of this experiment included the length of the stimuli and the type of the stimuli. Each variable had two levels, which created four conditions for each participant to experience. Length of stimuli was classified as either long or short and type of stimuli was categorized as either words or digits. Short words were created from four to five letters and long words were made up of eight to nine letters. Short numbers were created out of two digits and long numbers were made up from four digits. The font size of the stimuli was 24 and the font used was Arial. Each participant was expected to carry out four tests. The first test consisted of short words, the second test was long words, the third test was short digits and the fourth test was long digits. Each item was presented at five second intervals and a thirty seconds break between tests.

Procedure

Before beginning the experiment, a list of words and digits was created. A large number of words and digits were needed to ensure that none of the words or numbers would be repeated during the experiment. In addition, some of the selected words and digits would act as distractors during the experiment. At the end, 97 words were elected for the short words category and 100 words were selected for the long words category. To ensure that ethical standards for research were addressed, informed consents were gathered from each participant. They were then given instructions on how to complete the tests and record their results on a piece of paper that would be provided. Computer software was used to randomize the order at which the participants would take the test. Each test consisted of 10 items and there were four trials for each test. During the experiment, the participants were expected to sit in front of a computer and focus their attention on a fixation mark presented on the screen. A series of digits or letters depending on the test being taken was presented on the screen. After a series of ten stimuli were presented on each test, the participant was asked to identify the test items on a list presented to them on the screen. The list presented after each test consisted of the actual stimuli together with other distractor words or digits of the same category as the ones on the actual test. The participants were asked to use the mouse and click on 10 items they could recognize on the list from their memory. This procedure was used on all four tests. The computer was set in such a manner that it records the results of each participant’s after each test depending on the accuracy of response. After the experiment, the results for each participant were computed and an accuracy average generated for each and all tests. The results were recorded on paper and the participants were requested to provide demographic information such as their age, gender, ethnicity and academic level. This was done on questionnaires provided to each participant. After collecting this information, participants were debriefed and thanked for their involvement and assistance in carrying out the experiment.

Results

After the data was collected and recorded, the analysis process was implemented. The aim of this analysis was to organize the accuracy level of each participant in regard to the tests conducted and to determine and identify the relationship that exists between the means of the four tests for each participant. The results indicated that the length of the stimuli had a significant effect on the recognition capabilities of the participants. It was noted that the participants easily remembered short stimuli with accuracy as compared to accuracy levels recorded for long stimuli. On the same note, the results showed that the type of stimuli greatly affected the recognition abilities of the participants such that words were easily remembered than numbers. These two main effects indicated that there is a close relationship between the length and type of stimuli. The effect of the length of the stimuli relied on whether the stimuli are words or digits. Further analysis of the results suggested that when participants were presented with words, their accuracy increased with an increase in length. However, when doing the digit test, the accuracy of the participants in recalling the test stimuli accurately decreased as length increased as can be illustrated in the chart below.
Chart 1: Effect of Stimuli Length and Type on Accuracy [pic]

Discussion

According to the result gathered during this experiment, the independent variables (length and type of stimuli) had a significant effect on the dependent variable (recall accuracy). As expected, participants easily recalled short digits more than they did long numbers and recognized more long words than they did long numbers. This supports previous studies, which indicated that words are easily remembered as compared to numbers, because words are abstract to memory thus hard to remember, while words are read with automation (Thorn & Page, 2009, p. 208). These assertions are supported by (Dehn, 2011) who stated that people were more likely to remember short words than long words. However, this hypothesis has been questioned by the results of this experiment due to the following reasons. First of all, the participants are students and reading comes to them automatically because they are required to do a lot of reading. Due to their educational level, they are expected to grasp long words due to the complexity of their courses. Secondly, the words selected for the tests were familiar words, which could easily be remembered by students. According to Solso (2005) and Byrne (2009, p. 152), words that have been used regularly are easily remembered. This could explain why the participants found it easy to remember the long words. Despite these revelations, the results of this research do not address the capacity of items the short term memory can hold before they are processed to the long term memory stores and whether the number seven is the ultimate number as suggested by previous research. This presents an avenue through which further research can be conducted on this topic.

Conclusion

Cognitive psychology presents a platform, which can be used to better understand brain functions. This report set out to transcribe the events that took place in a research that aimed to explore the effects length and types of stimuli have on the short term memory accuracy of selected participants. The experimental research methodology was used and the lab design was implemented. The results from the experiment indicates that exposure to particular words expands an individual’s short term memory thereby enabling him/her to recognize more long words. However, this research as also indicated that there is need for more comprehensive research that seeks to concisely identify the number of items our short term memory can store within a given period of time.

References

Brown, C 2006, Cognitive Psychology, Sage, New York.
Byrne, JH 2008, Concise Learning and Memory: The Editor's Selection, Academic Press, New York.
Dehn, MJ 2011, Working Memory and Academic Learning: Assessment and Intervention, John Wiley & Sons, Boston.
Solso, RL 2005, Cognitive Psychology, Pearson Education, Inc., Boston, Massachusetts.
Thorn, A & Page, M 2009, Interactions between Short-Term and Long-Term Memory in the Verbal Domain, Taylor & Francis, California.
Zastrow, C & Kirst-Ashman, KK 2009, Understanding Human Behavior and the Social Environment, Cengage Learning, New York.