Memory Process Serial Position Effect - Lab Report Example

Introduction During our day, we are faced with situation were we must memorize different things. Scientists have been concerned to understand how weremember things. We usually try to remember things not carrying about their order or location which is called free recall (MacKewn & Goldthwaite, 2004). However, many researchers found that the position of things is a matter in remembering them which is referred to as the serial position effect. Items at beginning or end of a list are easier to remember than those in middle of list. This phenomena is referred to as the primacy or recency effect. Atkinson & Shiffrin (1968) tried to explain the primacy serial position effect as a result of the greater attention allocated to the first and last items on a list. This improves the probability of recalling such items in long-term memory. They explained recency serial position effect as being recalled by short-term memory as last items were last viewed through the list. Rundus (1971) proved that participants devoted more rehearsal to items first in list. Welch & Burnett (1924) further proved that primacy effect was reduced and items first in list were not stored in long-term memory when participants were asked to only rehearse items while they were being presented. Glanzer & Cunitz (1966) showed that items presented at faster rates provides less rehearsal time by participants which reduced primacy effect. The recency effect was also proved to be related to short term memory by requesting participants to do something else before testing their memory of items. Both, Glanzer & Cunitz (1966) proved that the recency effect is explained by short-term memory account by introduction a distracter activity after last items on a list such as a small arithmetic question. They found that recency effect was reduced by such distractors. The following experiment investigates the serial position effect.This is accomplished by recalling of alphabet letters using a software simulation program. Hypothesis to be tested was that structural retention occurs faster than semantic and phonemic retention. Method Participants The participants in the experiment consisted of University undergraduates enrolled in a Cognitive Psychology course. Apparatus The experiment was conducted by use of computers install in Lab. Each computer ran the simulation psychology program Psyktrek 3.0. Participant used a standard mouse to enter their input in the computer. during the experiment. Procedure Participants were positioned in front of a computer which ran the simulation program Psyktrek 3.0. Once the CD was loaded on the computer, a selection of different types of experiments is displayed on the screen. The Memory Processes Serial Position option was pressed using the mouse.The program presents a page with one side of blank space and the other side with buttons representing each letter of the alphabet. Each trial consists of a sequence of six letters which are presented separately. Each letter was displayed for one second. All letters on the side become clickable once the letters are hidden. Each respondent uses his mouse to click on the letters he recognize in any order. The program waits for participants to select six letters then it stops receiving participants input. The program records the time taken to enter all choices. Participants then pressed the Next trial button to go to the next sequence of letters until six trials are conducted. After participants complete all six trials, results of correctly recognized and recalled lettes are displayed. These results include tabular and graphical presentation of the percentage of correctly recalled items together with a list of presented letters. Results Data for participant number 7 and 8 were removed due to procedural error in recalled results. Recall and Recognition: Descriptive analysis of the data shown in appendix I, reveals that the mean average of recalled letters was (9.3) with standard deviation of 4.4. This accounts to 22.4% of all letters displayed. The mean average of recognized letters was (30.4) with standard deviation of 4.6. This means that 82.9% of all letters displayed were recognized by participants. The following graph demonstrates the recall and recognition data graphically. Figure 1: Recall and Recognition Data about their mean. Figure 1 demosntrates the existance of outliers in the recall data at participants number 2 and 20. Outliers within recognition data lies at participants number 5, 20 and 21. The above figure clarifies how recognition data varies about its mean of (30) with standard deviation of 4. It also clarifies how recall data varies about its mean of (9) with standard deviation of (4). Higher deviaiton is found in recall data due to the existance of more outliers. T-test was conducted on the difference between the mean of both recall and recognition data. P-value was less than alpha level of .05. The means of both groups are different and mean for recall is larger than mean of recognition. Serial Position Groups: The mean of the number of correctly recalled letters within the six groups are 5.4, 5.2, 4.8, 5, 4.5, and 5.1 respectively with standard deviation of 1.3, 1.0, 1.2, 0.7, 1.2, 1.1. Statistical analysis of the difference among groups demonstrates that the means of all 6 groups are not different. The overall mean of all groups is 5.0. Participants on average recognized five out of six characters in each trial. Analysis of Retention: The mean for structural retention was 8.3 with standard deviation of 2.1. The mean for Phonemic retention was 10.6, with standard deviation of 1.8. The mean for semantic retention was 11.2 with standard deviation of 1.5. Statistical analysis of the difference between means prove that the mean for semantic retention is larger than the mean of phonemic retention which is also larger than structural retention. Analysis of Retention Time: As shown in appendix II, the mean time for structural retention was 1.8 with standard deviation of 0.6. The mean for Phonemic retention was 2.9, with standard deviation of 1.2. The mean for semantic retention was 3.0 with standard deviation of 1.8. Statistical analysis of the difference between the time for structural, phonemic and semantic retention proved that structural retention occurs as the shortest duration of 1.8 which is less than both phonemic and semantic retention. Discussion The results of the experiment confirmed the serial position effect. Descriptive analysis of recalled and recognized characters revealed that 82.9% of letters were recognized while 22.4% of characters were recalled. It was also found that more semantic retention occurred than phonemic retention which also occurred more than structural retention. However, it was faster to recognize structural retention from short memory than phonemic and semantic retention. References Atkinson, R. C., & Shiffrin, R. M. (1968). Human memory: A proposed system and its control processes. Psychology of learning and motivation: II, 249. MacKewn, A., & Goldthwaite, D. (2004). CogLab on a CD. Belmont: Wadsworth. Glanzer, M., & Cunitz, A. R. (1966). Two storage mechanisms in free recall. Journal of Verbal Learning & Verbal Behavior, 5, 351-360. Reed, S. K. (2004). Long-Term Memory. In Cognition Theory and Application (pp. 97-124). Belmont: Wadsworth. Rundus, D. (1971). Analysis of rehearsal processes in free recall. Journal of Experimental Psychology, 89, 63-77. Welch, G. B., & Burnett, C. T. (1924). Is Primacy a Factor in Association-Formation. American Journal of Psychology, 35, 396-401. Appendix I: Descriptive Analysis of Group counts Group 1 Group 2 Group 3 Mean 5.4 Mean 5.16 Mean 4.76 Standard Error 0.251661148 Standard Error 0.205589 Standard Error 0.24 Median 6 Median 5 Median 5 Mode 6 Mode 6 Mode 5 Standard Deviation 1.258305739 Standard Deviation 1.027943 Standard Deviation 1.2 Sample Variance 1.583333333 Sample Variance 1.056667 Sample Variance 1.44 Kurtosis 6.056036701 Kurtosis 2.085545 Kurtosis 0.529945 Skewness -2.482361557 Skewness -1.34575 Skewness -1.06859 Range 5 Range 4 Range 4 Minimum 1 Minimum 2 Minimum 2 Maximum 6 Maximum 6 Maximum 6 Sum 135 Sum 129 Sum 119 Count 25 Count 25 Count 25 Confidence Level(95.0%) 0.519403077 Confidence Level(95.0%) 0.424314 Confidence Level(95.0%) 0.495336 Group 4 Group 5 Group 6 Mean 5 Mean 4.52 Mean 5.12 Standard Error 0.141421 Standard Error 0.231805 Standard Error 0.225979 Median 5 Median 5 Median 6 Mode 5 Mode 5 Mode 6 Standard Deviation 0.707107 Standard Deviation 1.159023 Standard Deviation 1.129897 Sample Variance 0.5 Sample Variance 1.343333 Sample Variance 1.276667 Kurtosis 1.72332 Kurtosis 2.213129 Kurtosis 0.874569 Skewness -0.76859 Skewness -1.1871 Skewness -1.19539 Range 3 Range 5 Range 4 Minimum 3 Minimum 1 Minimum 2 Maximum 6 Maximum 6 Maximum 6 Sum 125 Sum 113 Sum 128 Count 25 Count 25 Count 25 Confidence Level(95.0%) 0.291879 Confidence Level(95.0%) 0.478421 Confidence Level(95.0%) 0.466398 Appendix II: Descriptive Analysis of Retention counts Structural Phonemic Semantic Mean 8.28 Mean 10.6 Mean 11.24 Standard Error 0.434051 Standard Error 0.365148 Standard Error 0.301552 Median 8 Median 11 Median 12 Mode 7 Mode 11 Mode 12 Standard Deviation 2.170253 Standard Deviation 1.825742 Standard Deviation 1.507758 Sample Variance 4.71 Sample Variance 3.333333 Sample Variance 2.273333 Kurtosis -0.82781 Kurtosis 3.141759 Kurtosis 12.6246 Skewness -0.15287 Skewness -1.84856 Skewness -3.29838 Range 8 Range 7 Range 7 Minimum 4 Minimum 5 Minimum 5 Maximum 12 Maximum 12 Maximum 12 Sum 207 Sum 265 Sum 281 Count 25 Count 25 Count 25 Appendix III: Descriptive Analysis of Retention Times Structural Phonemic Semantic Mean 1.834286 Mean 2.949524 Mean 3.053048 Standard Error 0.137107 Standard Error 0.270801 Standard Error 0.385661 Median 1.65 Median 2.64 Median 2.7 Mode #N/A Mode 1.57 Mode 4.24 Standard Deviation 0.628304 Standard Deviation 1.240965 Standard Deviation 1.767319 Sample Variance 0.394766 Sample Variance 1.539995 Sample Variance 3.123417 Kurtosis -0.70709 Kurtosis -0.31059 Kurtosis 3.188167 Skewness 0.493288 Skewness 0.672523 Skewness 1.253419 Range 2.16 Range 4.6 Range 8.216 Minimum 0.92 Minimum 1.06 Minimum 0.244 Maximum 3.08 Maximum 5.66 Maximum 8.46 Sum 38.52 Sum 61.94 Sum 64.114 Count 21 Count 21 Count 21 Read More