Effectiveness of Dual Tasks - Broadcast and Song - Lab Report Example

Measuring the effectiveness of dual auditory tasks (simultaneous) against a single auditory task Dual or multiple tasks are part of our everyday life. Sometimes people have to conduct very critical multitasks precisely at the same time. However according to the brain functions, for humans simultaneous multiple tasks are difficult due to limitations in the cognitive process. Therefore it is important to weigh the effectiveness divided attention of dual or multiple performances over single performance. This study was carried out to measure the effectiveness of the two auditory tasks against a single auditory task. Forty undergraduates of age 19-22 years were selected. They were randomly assigned to two groups consisting 20 in each group. A news broadcast and a song were identified as the two auditory tasks. Control group listened to the two auditory tasks separately and answered a question paper given. Experimental group listened to the both auditory tasks simultaneously and answered the question paper. According to the accuracy of the answers marks were given. Mean scores obtained by two groups were compared using two tailed Student’s T-Test for independent samples. Marks scored by the experimental group are significantly lower than that of the control group. It was concluded that dual simultaneous auditory tasks are highly ineffective when compared to separate occurrences. Introduction It is not uncommon to perform dual or multiple tasks at the same time in everyday life. Most of the individuals perform those tasks such as driving while talking or listening to music, reading while listening to music without a difficulty. On the other hand equipments providing multiple tasks have been produced to enhance the quality of life. As an example Multi-channel imaging systems are designed to provide two or more programs on the same screen to fulfill the requirement of multiple viewers (freshpatents.com, 2007). However, according to the findings on the subject of the brain functions, simultaneous performance of dual or multiple tasks is difficult for people due to limitations of the human cognitive process. It is widely thought that the brain focuses attention only on one task at a time (Mei-Ching, 2006). However some scientists believe divided attention is nearly effective as single task or even beneficial in some combinations. According to the findings dual tasks are sometimes important to reduce the occurrence of unfavorable outcomes to an individual who is performing a critical duty such as military mission (Pew, 1995). In addition to human brain functions there can be other factors which can affect the effectiveness of multitasking. Eysenck (2004) reviewed many dual tasks experiments conducted in the USA and found three possible factors which can interfere with the dual task performance. The first factor is known as Task similarity. It has been evidenced that effective dual task performances occurred mostly in dissimilar task which use different sensory stimulus such as visual-auditory and physical-auditory than similar tasks (Treisman, 1973). The second factor is the Practice, where the effectiveness of conducting dual tasks was greatly improved with the train. However some studies showed they were still not effective as single tasks. The third factor was the Difficulty or the complexity of the tasks been performed. It was found that the Effectiveness of simple dual tasks was higher than complex or dificult dual tasks (Eysenck, 2004). Irrespective to the ability of the brain and factors affecting, sometimes people have to handle critical multiple tasks simultaneously. As an example an air traffic controller who is receiving two important messages at the same time from two aircrafts is performing two critical auditory tasks. His ability to correctly interpret the both of them and make the right decision is very important since a small mistake in interpretation can lead to a huge disaster. Therefore determination of the effectiveness of dual or multiple tasks over single task is very important in many areas when assigning tasks and allocating manpower. In other hand it is beneficial to identify the appropriate dual tasks combinations which can conduct easier through scientific experiments (Mei-Ching, 2006). Common human tasks (excluding the mental process) can be categorized in to six groups as visual, auditory, oratory, physical, smelling and tasting and can have many dual combinations such as auditory-auditory, auditory-visual, visual-visual, oratory-auditory, and oratory-physical. It is interested to know whether someone can perform dual and single tasks with similar effectiveness, which dual combinations are effective and which dual combinations are extremely difficult. Simply, is it reasonable to allow people answer the phone while driving? Or should it be banned to protect the passengers and people on the road? In this study the effectiveness of the dual auditory tasks over single auditory task was measured considering the common occurrence and importance of dual auditory tasks. It was expected to find out the human ability to correctly understand and interpret two verbal messages when heard simultaneously compared to separate events. In general these findings will be helpful to understand the divided attention in auditory tasks and thereby minimize human errors in critical situations. The objective of this study was to measure the effectiveness of dual auditory tasks against single auditory task. The hypothesis tested was effectiveness of a single auditory task is significantly higher than that of the dual auditory tasks. Methods Subjects There were 40 undergraduates including between the ages 19 to 22. They were randomly selected from Johns Hopkins University. Students who preferred to participate in the trial within the given age range were instructed to provide their details to the experimenter. Experimenter selected the subjects until the required numbers were achieved and all of them were given a reference number at the time of selection. Persons who were having any type of hearing loss or mental illness or who cannot understand the English language properly were excluded. Twenty subjects were selected randomly from the total sample for the controlled group and the rest was considered as the experimental group. Materials This experiment required one I-Pod player. It was installed with a two-minute news broadcast containing several news items and a meaningful song approximately two minutes long, which had not been heard by the subjects before. Both were in English. A simultaneous recording of both the news and song was installed in the I-Pod player. There were three question papers. Paper one consisted of 10 multiple choice questions about the news item with 4 choices. Paper 2 consisted of 10 multiple choice questions about the song with 4 choices. Paper 3 had all above 20 questioned in a mixed order. Design This was a randomized controlled trial (RCT) which is commonly used to measure the effectiveness of a treatment or a particular situation. This was consisted of a control group and an experimental group. Twenty participants were randomly allocated for each group from the list of their names. Therefore there was no chance for selection biasness. The gender of the participants was not considered thereby any possible gender effect was not blocked in this study. Procedure This experiment was conducted in the Johns Hopkins library with a quiet environment. All participants were provided with the instruction sheet on the day of the experiment. Control and the experimental groups were further divided in to 4 sub groups of 5 participants. There were four experimenters and each one handle one sub divided experimental group and a control group. Four experimenters conducted their trials separately. Controls and experimental groups were advised to be seated in the library at 10.00 am and 10.45 am respectively. The experiment started at 10.00 am and question paper-1 was given to the controls to answer about the news item. Then the experimenter started with controls, one controller at a time. The news item was played while controller was listening to the Ipod using headphones and at the end allocated five minutes to mark the correct answers. Then the answer-sheets were collected. Then the question paper-2 was given to the same controller to answer about the song. The song was played for 2 minutes and at the end allocated 5 minutes to mark the correct answers and answer sheets were collected. Experimental trial was started at 10.45 am. The experimental group was given the question paper-3 to answer. Then each subject was advised to listen to the simultaneously record of news broadcast and song. At the end they were given 10 minutes to answer the questions and their answer sheets were collected. It was assumed that all the participants clearly heard the both audios and overlapping of sound waves did not occur and all the participants heard audios at the same intensity. Statistical analysis Data was entered in to a MS Excel Spreadsheet. Letters C and E were used to indicate the result of the control group and the experimental group respectively. Means and the Standard deviations of the scores of song and news broadcast within and between the groups were separately calculated. The means of the scores of control group and experimental group were compared using two tailed Student’s T- Test for independent samples at 0.05 significant levels. Mean scores within groups were also compared. Results General characteristics of the sample: All forty (40) participants were undergraduates between 19 and 22 years. They have been randomly and equally allocated to control and experimental groups. Figure 1 plots the frequency distribution of the total score obtained by each participant. It can be clearly seen participants of the control group (orange color) have scored higher marks than the experimental group (green color). Only 10% of the experimental group had scored more than 10 marks (out of 20) and mean score is 5.4. However 95% of the control group scored more than 10 marks with a mean of 12.7. Average score for whole sample (experimental + control) is 9.0 (SD= 4.32) Figure 2 compares the mean scores obtained for the song and news broadcast within the group. In both groups scores obtained for the song are lower than that of the news broadcast. According to the T-Test analysis in control group, mean score for song is significantly lower than the mean score of news broadcast (p=0.045) at 0.05 level. However the values are not statistically significant in experimental group. Figure 3 shows the mean score comparisons between control and experimental groups. Control group have higher scores for both song and news broadcast and total score as well. Average scores of control group are two folds higher than the average scores obtained by the experimental group. P-values resulted from T-Test of mean comparison between two groups are shown in Table 1. Mean scores for song, news broadcast and total marks are significantly lower (p Read More