Content-Type: text/html Identifying Structural Features of Radio: Orienting and Memory for Radio Messages Robert F. Potter [log in to unmask] Doctoral Candidate Annie Lang [log in to unmask] Associate Professor Paul Bolls [log in to unmask] Graduate Student Department of Telecommunications Institute for Communication Research Indiana University (812) 855-5824 Paper submitted to the Theory and Methodology Division of the Association for Education in Journalism and Mass Communication. Baltimore, MD March, 1998 Please Review This Version Identifying Structural Features of Radio: Orienting and Memory for Radio Messages Abstract This paper examines the ability of nine different structural and content features of radio to elicit orienting responses from radio listeners. It further tests the effect of the orienting response on listeners' memory for information presented immediately following the orienting eliciting feature. Results show that eight of the nine features elicit orienting responses. On average, memory is better for information presented following those features than it is for information presented before the features. Identifying Structural Features of Radio: Orienting and Memory for Radio Messages Are there features of broadcast radio which can affect how audio messages are cognitively processed by listeners? Previous research has demonstrated that structural features of video messages can be manipulated by producers to influence audience members' cognitive processing (Anderson, 1983; Basil, 1994; Calvert, Huston, Watkins & Wright, 1982; Geiger & Reeves, 1993; Grimes, 1990; Gunter, 1987; Lang, Dhillon & Dong, 1995) but results of this work have not been extended to other media such as radio. Radio producers have acknowledged the important role structural features such as sound effects and vocal delivery play in capturing audience attention (Keith, 1990; Siegal, 1992). However, specific investigations into which structural features influence cognitive processing of radio messages have not been conducted. The goal of this study is to identify possible structural features of radio messages and examine their influence on the processing of message information. Over the last 20 years research has attempted to identify the structural or formal features of television which alter television viewers' attention to and memory for television messages. This work began in the seventies with studies examining what aspects of children's television caused children to look at the TV (Anderson, Levin, & Lorch, 1977, Anderson, Lorch, Field, & Sanders, 1981, Anderson, 1983). It was suggested (Singer 1980) that many of the formal features of television identified in this research were actually eliciting orienting responses from child viewers. An orienting response (Lynn, 1966) is a reflexive attention response characterized by a group of behavioral and physiological responses including looking toward the stimulus that elicited the response, a slowing of the heart rate, and an increase in skin conductance. Further research determined that many structural features of television, including cuts (Lang, Geiger, Strickwerda, & Sumner, 1993), negative video (Lang, Newhagen, & Reeves, 1998), video- graphics (Thorson & Lang, 1992), and movement (Lang, 1990, Reeves, Thorson, Rothschild, McDonald, Hirsch, & Goldstein, 1985) all elicited orienting in attentive television viewers. What was not clear, was whether the increase in attention elicited by these structural features increased or decreased memory for the messages (Anderson, 1983; Singer, 1980). One view was that these momentary increases in attention would automatically increase memory for the messages. The other view was that these involuntary responses would distract viewers from the message content and focus their attention instead on the peripheral or structural aspects of the message. Research investigating this question suggests that both things can happen depending on how hard the viewer is working to learn the content contained in the message. For example, Thorson and Lang (1992) showed that when television viewers were watching easy or familiar content, memory for that content improved immediately following a video-graphic which elicited an orienting response. However, when the content was difficult or unfamiliar, memory decreased following the video-graphic. Similarly, Lang et al. (1993) demonstrated that when the content on either side of a cut was related, memory following the cut increased. However, when the content on either side of the cut was unrelated, memory decreased. Similar results have been found when looking at memory for television messages as a function of how many structural features they contain. If the content of a message is not demanding, then viewers' memory for that content improves when the message contains many structural features and elicits many orienting responses. However, if the message content is demanding, then memory for the content of the message is lower if there are a lot of structural features in the message (Lang, Bolls, Potter, & Kawahara, in press). To date, this model has been applied almost exclusively to studying television messages. Very little research has been done to determine if these same effects might be found in media other than television. Potter, Bolls, and Lang (1997) conducted a study to determine if radio listeners exhibited orienting responses to structural features of radio. In that study, several radio structural features were combined to determine if listeners exhibited cardiac orienting responses to these combined structural features. The answer was yes. This paper extends that work by examining individually the specific structural features, which were combined in the previous study, to determine if they elicit orienting responses in radio listeners. Nine different structural features and sound effects were combined in the previous study to test the basic orienting hypotheses. The nine features are voice changes, commercial onsets, silence, jingle onsets, laser sound effects, a channel changing sound effect, a phone ringing, a funny voice, and a sexual word. It is expected that at least some of these structural and content features of radio will elicit orienting in radio listeners. If this occurs, then listeners should exhibit a decrease in heart rate and an increase in skin conductance following the structural feature of interest. Thus: H1: Heart rate should decrease immediately following the onset of an identified structural or content feature. H2: Skin conductance should increase immediately following the onset of an identified structural or content feature. This paper goes on to test the effects of these sound effects on radio listeners' memory for the content occurring immediately before and immediately after the various structural and content features. Given the nature of the stimulus (light radio content taped directly off-air) it is expected that listeners will not find the content to be demanding. If that is the case, then the orienting responses should increase memory for information immediately following the identified structural feature. This leads to: H3: Information presented immediately after the onset of an identified structural or content feature will be recognized better than information presented immediately before such a feature. H4: Information presented immediately after the onset of an identified structural or content feature will be recognized faster than information presented immediately before such a feature. Methodology Subjects Subjects were college students enrolled in one of three telecommunications courses at a major Midwest university. Each subject received course credit for their participation. Thirty-eight subjects participated in the experimental protocol. Stimulus Preparation and Description The experimental design called for the creation of audio stimuli containing elements believed to cause orienting responses in radio listeners. Both structural and content elements were chosen. The structural features chosen for investigation were: laser sound effects, voice changes (the onset of a different speaker), commercial onsets, and silence. The more content oriented features chosen were a funny voice, a jingle onset, a telephone ringing, the sound of someone changing stations, and the presence of sexual content. The final twelve minute stimulus tape included seven audio messages. Six of these messages were recorded off the air in a Midwest college town. The seventh message was a rock and roll song recorded directly from compact disc. Four tape orders were constructed using the seven messages. All of the structural features of interest occurred during the six non-song messages. The song was the fourth element in all four tape orders, with the six broadcast messages being placed in different logical orders around it. No broadcast message appeared exclusively before or exclusively after the song. Also no two broadcast messages were adjacent to each other in more than one tape order. The tape orders were transferred onto the audio track of a VHS videotape which had been blacked and time coded. This allowed the exact location of the features to be determined. Dependent Variables The dependent variables in this study are heart rate, skin conductance, and recognition accuracy. Heart rate and skin conductance were used to indicate if orienting occurred. If orienting occurs there should be a significant deceleration of the heart occurring in the six seconds following onset of the structural feature (Lang, 1990) and a significant increase in skin conductance (Lynn, 1966) immediately following the feature. Memory for the content of the messages was measured using a forced choice reaction time recognition test. This means both percent accuracy of recognition and speed of recognition can be ascertained. Experimental Procedure There were four experimenters who conducted this study; each followed the same experimental protocol designed to obtain data on human reactions to and memory for television, computer media, and radio. The radio protocol reported in this section was always the second set of procedures subjects participated in. Prior to the subjects arrival, a series of safety checks was conducted on the data collection equipment to ensure the safety of the subjects. Only one subject participated in the experiment at a time. Each was greeted by the experimenter, who then explained that the purpose of the study was to gain a better understanding of how human beings react to the media, specifically television and computers. After obtaining informed consent, Beckman AG/AGCL electrodes were applied to the subject's arms and hands to measure heart rate and skin conductance. The first set of procedures involved either watching a set of television messages or interacting with a computer monitor and keyboard. After these procedures were completed, subjects were told that the researcher needed to take about ten minutes to do some calculations on the data which had just been collected. The researcher told the subject that, in the meantime, radio messages would be played for them to listen to. After the radio messages were played, subjects participated in other portions of the protocol dealing with the television and computer interactions. When these were completed, subjects were given a recognition memory test for the radio messages. This test consisted of listening to 3-second portions of audio messages. The subjects were told that some of the portions were from messages they had heard previously, and others were not. Using a joystick held in their dominant hand, subjects were instructed to answer as soon as they knew whether or not they had heard the portion earlier in the experiment. After the entire protocol was completed, subjects were debriefed, thanked, and dismissed. Apparatus Heart rate and skin conductance were collected from the subjects as they listened to the radio stimulus. The stimulus tape was played by a Panasonic videocassette recorder through the speakers of a 19-in. television placed approximately 5 feet from the subject. The videocassette recorder, experimenter, and physiological recording equipment were separated from the subject by an 8-foot wooden wall. The lab was controlled by a 386 computer with a LabMaster AD/DA board installed. Coulbourne physiological equipment was used in the collection of data. Heart rate was measured as the milliseconds between heart beats and was analyzed as the average heart rate per second. Skin conductance data were collected as an analog signal sampling at 10 times per second. Recognition responses were recorded using a Sidewinder joystick. Subjects would press the "yes" button on the joystick if they had heard the audio segment before, and the "no" button if they had not. Recognition results were coded for accuracy and response latency on a 386 computer using the Slimy Recognition/Reaction Time program (Newhagen, 1993). Analyses The heart rate data were analyzed using a mixed N (Repetitions) X 7 (Seconds) X 4 (Order) ANOVA. The within subjects factors were repetitions (with N levels representing the number of times an individual feature occurred) and Seconds (with 7 levels, representing 1 second prior and 6 seconds following feature onset). The number of repetitions of the feature varies from 1 to 5 depending on which feature is being analyzed. The stimulus tape included 5 voice changes, 2 examples of silence, 2 production effects, 2 commercial onsets, 2 jingles, 1 channel change, 1 phone ring, 1 sexual content, and 1 funny voice. The between subject factors was Order (with four levels representing the presentation orders). Missing heart rate data were re-coded to the mean heart rate across subjects for that second. 8 values out of 6840 were missing, resulting in 0.12% of the heart rate data being re-coded to the mean. The skin conductance analysis was done on the change scores; that is, the extent to which skin conductance levels changed after the onset of the structural features (Dawson, Schell, & Filion, 1990). The data were analyzed using a N (Repetitions) X 4 (Seconds)X 4 (Order) ANOVA. The within and between subjects factors for this analysis were the same as above except that the Seconds factor had 4 levels, representing the change scores for the 4 seconds following the feature onset. Due to researcher error during data collection, skin conductance data from three subjects were missing. Therefore, n=35 for the skin conductance analysis. The recognition data were analyzed using an N (Repetitions) X 2 (Position) X 4 (Order) ANOVA. The within and between subjects factors for this analysis were the same as above except for the Position within subjects factor which had two levels, before and after. These levels corresponded to whether the 3-second audio portion being tested occurred before or after the structural feature. Power As discussed above, the number of repetitions for the individual structural features varies from 1 to 5. As a result, the power to detect effects varies. Those analyses with four or five repetitions are much more powerful than those with a single repetition. Because the goal is to begin to explore which structural features may elicit orienting and because for several of these features power is quite low, the .10 level of alpha has been designated as significant for this study. Results Hypothesis 1 This hypothesis predicted that heart rate should decrease immediately following the onset of an identified structural or content feature. Using trend analysis, significant heart rate decelerations were found for voice changes (F(1,29) = 5.244, p<.066), commercial onsets (F(1,29)=8.01, p<.008), jingle onset (F(1,29)=3.03, p<.093), silence (F(1,29)=3.24, p<.082), production effects (F(1,29)=3.24, p<.018), phone ringing (F(1,29)=2.86, p<.10), funny voice (F(1,29)=4.973, p<.033) and sexual content (F(1,29)=10.05, p<.003. A significant deceleratory trend was not found for the station change sound effect. Thus, eight of the nine features tested showed significant cardiac deceleration following onset. Combining the features in an overall analysis also yielded a significant quadratic heart rate deceleration ( F (1,29)=13.32, p<.001). This combined effect is shown in Figure 1. Hypothesis 2 This hypothesis predicted that skin conductance should increase immediately following the onset of an identified structural or content feature. This hypothesis was not supported for any of the individual features, though the means are in the expected direction for six of the nine effects. When all the features are combined, there is a significant increase in skin conductance (F(3,81)=2.77, p<.047, epsilon squared = .06) which is shown in Figure 2. Hypothesis 3 This hypothesis predicted that information presented immediately after the onset of an identified structural or content feature will be recognized better than information presented immediately before such a feature. The results of this analysis are shown in Table 1. Of the nine features tested three showed significant effects in the predicted direction: voice change (F(1,34)=14.61, p<.001), funny voice (F(1,34)=3.86, p<.058), and sexual content (F(1,34)=4.39, p<.044). For all of these, recognition was better following the feature than it was before the feature. Commercial onsets also elicited a significant effect but in the opposite direction from that predicted (F(1,34)=5.11, p<.030) with 54% recognition for information presented after the commercial compared to 77% before. The remaining five features all had means in the correct direction but did not reach significance. When combined, however, the overall effect was significant (F(1,34) = 9.15, p<.005), with listeners recognizing 71% of the content before a feature compared to 77% after. Hypothesis 4 This hypothesis predicted that listeners would reach their recognition decisions faster for information presented following a feature than they would for information presented before a feature. The results of this analysis are presented in Table 2. This hypothesis was supported for only two of the features, voice change (F(1,34)=6.48, p<.016) and jingle onset (F(1,34)=8.85, p<.005). In both of these instances, latency to recognition was faster for information presented following the feature than it was for information presented before the feature. For two other features, commercial onset (F(1,34)=73.81, p<.001) and station change (F(1,34)=5.12, p<.030) this effect was significant but in the wrong direction. For the remaining five features the effect was not significant. The overall combined effect was also not significant (F<1). Discussion Overall the results of this study suggest that radio listeners, like TV viewers, have orienting responses to structural and content features of the medium. Further, there is evidence that these orienting responses do increase memory for the information that follows them. First, it seems to be fairly clear that radio listeners have orienting responses to structural features. Eight of the nine features tested in this study showed significant cardiac orienting responses (i.e., a significant quadratic deceleration of heart rate following the structural features). While the skin conductance data did not yield significant results for the individual tests, the overall combined test did show a significant increase in skin conductance. The effects of those orienting responses on memory is, not surprisingly, less clear cut. Overall, memory is somewhat better for information occurring after the feature than it is for information occurring before the feature, as predicted. The main exception occurs for commercial onsets and several possible explanations might be offered for this. First, as discussed previously, it has been demonstrated (Lang, Geiger, Strickwerda, & Sumner, 1993) that when processing television messages, memory for information following a cut decreases if the information is semantically unrelated to what was occurring before the cut. This lack of relation is exactly the condition tested by commercial onsets in radio. The beginning of a commercial usually introduces completely new and unrelated information to the listening audience. Thus, following the onset of a completely unrelated message, memory may decline as it does in television. A second possibility is that listeners may be actively avoiding paying attention to commercials. The latency results do not strongly support the notion that information presented immediately following a structural feature is somehow more available than information presented before the feature. However, this may partially be an effect of the design. For example, for voice changes which occurred within a single message with related content and for which there are several repetitions there is a significant effect in the predicted direction. It may be that there are too many uncontrolled content factors and insufficient power in this design to see latency effects consistently across these features. It is probably too early to conclude that no such effect exists. Practically, it seems safe to conclude that both structural and content features in radio do elicit orienting and that when content is not very demanding those orienting responses may increase memory for information occurring immediately following the feature. Further, even a fairly innocuous and common feature like voice change appears to consistently elicit both orienting and improved memory. This may mean that, despite the low cost, using only one announcer or anchor to deliver a radio advertisement or news story may be a poor production strategy. Results from this study suggests even a very small production effect (like the addition of a second voice) appears to significantly increase listeners' memory. This study also suggests that the addition of sound effects (phones ringing and stations changing) also appear to increase attention and memory. Finally things which are distinctions, like funny voices or sexual words, also appear to elicit orienting and improve memory for the content of the message. References Anderson, D. R., Levin, S. R., & Lorch, E. P. (1977). The effects of TV program pacing on the behavior of preschool children. AV Communication Review, 25. Anderson, D. R., Lorch, E. P., Field, D. E., & Sanders, J. (1981). The effects of TV program comprehensibility on preschool children's visual attention to television. Child Development, 52, 151-157. Anderson, D. R. (1983). Looking at television: Action or reaction, Children's understanding of television (pp. 1-32): Academic Press, Inc. Basil, M. (1994). Multiple resource theory I: Application to television viewing. Communication Research, 21, 177-207. Calvert, S.I., Huston, A.C., Watkins, B.A., & Wright, J.C. (1982). 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The effects of television videographics and lecture familiarity on adult cardiac orientg responses and memory. Communication Research, 19(3), 346- 369. Table 1: Mean recognition accuracy for information presented before and after the structural feature. Structural Feature Before After F df p Funny Voice .771 .914 3.86 1,34 .058 Station change .514 .600 <1 1,34 .373 Commercial onset .771 .543 5.11 1,34 .030 Jingle onset .715 .786 1.98 1,34 .170 Phone ringing .943 .886 <1 1,34 .422 Laser effect .629 .714 1.21 1,34 .280 Sexual content .857 .971 4.39 1,34 .044 Silence .672 .729 2.32 1,34 .137 Voice change .552 .762 14.61 1,34 .001 All .706 .771 9.15 1,34 .005 Table 2: Mean latency to reaction time for information presented before and after the structural feature. Structural Feature Before After F df p Funny Voice 3162 3128 <1 1,34 .865 Station change 3037 3429 5.12 1,34 .030 Commercial onset 2408 4153 73.81 1,34 .000 Jingle onset 2955 2533 8.85 1,34 .005 Phone ringing 3013 2877 1.08 1,34 .307 Laser effect 3277 3106 1.01 1,34 .322 Sexual content 2678 2745 <1 1,34 .664 Silence 2978 3178 .72 1,34 .402 Voice change 3284 3049 6.48 1,34 .016 All 3041 3068 <1 1,34 .542 Figure 1: Average heart rate change over time following a structural or content feature Figure 2: Average Skin Conductance over time following a structural or content feature