Divided attention between lyrics and tunes of operatic songs: evidence for independent processing.

Excerpts from French operatic songs were used to evaluate the extent to which language and music compete for processing resources. Do these two dimensions conflict? Are they integrated into a single percept? Or are they independent? The final word of each excerpt was either semantically congruous or incongruous relative to the prior linguistic context and was sung either in or out of key. Participants were asked to detect either the semantic or the melodic incongruity (single task) or both (dual task). We predicted a dual-task deficit if these tasks conflicted and no deficit if they were either independent or integrated. In order to distinguish between these last two outcomes, trial-by-trial contingency analyses were also computed, predicting no correlation if the tasks were conflicting or independent, a positive correlation under the assumption of integration and a negative correlation if dividing attention is impossible. Our results show similar levels of performance in single and dual tasks and no correlation between dual-task judgments, thus suggesting that semantic and melodic aspects of language are processed by independent systems. In addition, a comparison between musicians and nonmusicians shows that these conclusions are independent of musical expertise.     

Two-way interactions between music and language: Evidence from priming recognition of tune and lyrics in familiar songs

A priming technique was employed to study the relations between melody and lyrics in song memory. The procedure involved the auditory presentation of a prime and a target taken from the same song, or from unrelated but equally familiar songs. To promote access to memory representations of songs, we varied the format of primes and targets, which were either spoken or sung, using the syllable /1a/. In each of the four experiments, a prime taken from the same song as the target facilitated target recognition, independently of the format in which it occurred. The facilitation effects were also found in conditions close to masked priming because prime recognizability was very low, as assessed in Experiment 1 by d' measures. Above all, backward priming effects were observed in Experiments 2, 3, and 4, where song order was reversed in the prime-target sequence, suggesting that words and tones of songs are not connected by strict temporal contingencies. Rather, the results indicate that, in song memory, text and tune are related by tight connections that are bidirectional and automatically activated by relatively abstract information. Rhythmic similarity between linguistic stress pattern and musical meter might account for these priming effects.     

Divided attention: Evidence for coactivation with redundant signals

Many models of divided attention assume that signals presented on different channels produce separate activations, any one of which can initiate a response. According to these models, detection responses are especially fast when signals are presented on two channels at the same time because the system can detect a signal in either of two ways. Such models predict a testable relation among reaction time distributions for conditions in which a single signal is presented as compared with a condition in which two signals are presented, and this prediction is tested in two tasks. A bimodal detection task required a simple speeded response to either a visual or an auditory signal. A letter search task required a choice response depending on whether or not a two-letter display included the signal letter “A.” Data from both tasks are inconsistent with the prediction. When two signals are presented, responses are faster than separate-activation models can explain. The results favor “coactivation” models, in which signals presented on different channels contribute to a common pool of activation that initiates a response.     

Divided attention and prerecognition processing of spoken words and nonwords

Three recognition memory experiments examined phonemic similarity and false recognition under conditions of divided attention. The manipulation was presumed to have little effect on automatic, perceptual influences of memory. Prior research demonstrated that false recognition of a test word (e.g., discrepancy) was higher if the study list included a nonword derived from the future test word by changing a phoneme near the end of the item (e.g., discrepan/l/y) relative to an early phoneme change (e.g., /l/iscrepancy). The difference has been attributed to automatic, implicit activation of test words during prerecognition processing of related nonwords. Three experiments demonstrated that the late-change condition also contributed to higher false recognition rates with divided attention at encoding. Dividing attention disrupted recognition memory of studied words in Experiments 1 and 3. Results are discussed in terms of their relevance for an interpretation emphasizing the automatic, implicit activation of candidate words that occurs in the course of identifying spoken words and nonwords.     

Divided attention between simultaneous auditory and visual signals

Past studies of simultaneous attention to pairs of visual stimuli have used the “dual-task” paradigm to show that identification of the direction of a change in luminance, whether incremental or decremental, is “capacity-limited,” while simple detection of these changes is governed by “capacity-free” processes. On the basis of that finding, it has been suggested that the contrast between identification and detection reflects different processes in the sensory periphery, namely the responses of magno- and parvocellular receptors. The present study questions that assertion and investigates the contribution of central processing in resource limitation by applying the dual task to a situation in which one stimulus is auditory and one is visual. The results are much the same as before, with identification demonstrating the tradeoff in performance generally attributed to a limited capacity but detection showing no loss compared with single-task controls. This implies that limitations on resources operate at a central level of processing rather than in the auditory and visual peripheries.     

Divided attention modulates semantic activation: Evidence from a nonletter-level prime task

Research has recently shown that semantic activation is modulated in proportion to the amount of attention required for letter-level processing of the prime (the attention modulation hypothesis; Smith, Bentin, & Spalek, 2001). In this study, we examined this hypothesis with an auditory divided-attention task. Participants were asked to decide whether the pitch of a probe tone presented with the prime word was higher or lower than the basic tone presented with the fixation cross. Their target task was lexical decision to the target word. Experiment 1 showed that semantic priming was modulated by the amount of attentional resources. Moreover, in Experiment 2, this modulation was also found in a situation that eliminated the possibility of participants' response strategies. Yet, Experiment 3 showed repetition priming to be unaffected. These results support an amended attention modulation hypothesis in which modulation is not limited to letter-level processing.     

Negative priming between pictures and words in a selective attention task: Evidence for semantic processing of ignored stimuli

This study examined the processing of ignored pictures and words when attention was directed to a different picture or word. Previous work by Tipper (1985) demonstrated that the priming effect of an ignored picture on a subsequent categorically related picture is inhibitory. This effect was termednegative priming. Tipper concluded that ignored pictures achieved abstract categorical levels of internal representation, and that these representations were inhibited during selection of a simultaneously presented picture. This conclusion, however, was premature. Observation of the figures used by Tipper suggests that objects within a category have greater structural similarity than do objects in different categories. The negative priming effect could therefore be at a structural level of representation. The present study examined priming across symbolic domains (pictures and words) where there was no structural relationship between objects. Negative priming was again observed and was equivalent to the negative priming observed within symbolic domain. These data suggest that ignored drawings and words do achieve abstract categorical levels of representation, and that the mechanisms underlying negative priming operate at, or beyond, this level.     

Evidence for independent processing of subjective contour brightness and sharpness.

Subjective contours have been of considerable interest because of their importance to theories and physiological models of form perception. In particular, they have recently been characterized as the result of magnocellular cortical processing. There is, however, a paucity of parametric data relating to basic psychophysical parameters in this field. Two experiments are reported in which the roles of subjective contour size, retinal eccentricity, and flicker rate in subjective contour salience were investigated. Eleven observers estimated subjective contour magnitude using an Ehrenstein configuration. Configurations ranging in size from 0.25 to 3 deg were presented to three retinal loci (fovea, 2 deg, and 4 deg) at flicker rates ranging from 5 to 15 Hz. Subjective contour brightness and distinctness were measured separately. Brightness was greatest at a subjective contour size of about 1.25 deg, at flicker rates of 5-7 Hz, and at 3 deg peripheral for all flicker rates and all but the smallest stimulus sizes. Distinctness decreased with eccentricity and flicker, but remained high at small diameters (thus implicating spatially sensitive mechanisms). Taken together, the results support a magnocellular processing of subjective contours with respect to brightness, but also suggest that there is a parvocellular contribution to subjective contour sharpness.     

Switching attention within and between categories: Evidence for intracategory inhibition

In a variation of the Posner and Snyder (1975b) paradigm, subjects made speeded “same” or “different” responses to pairs of digits or letters on the basis of name identity (Experiment 1) or physical identity (Experiment 2). Each target pair was preceded by an informative (letter or digit) or noninformative (plus-sign) warning signal. The letter or digit represented by an informative warning signal had a high probability of appearing in the subsequent target pair (expected condition). On trials in which the expected stimulus did not appear in the target pair, the target pair belonged with equal probability to either the same category (either letters or digits) as the expected stimulus or to the opposite category (unexpected-similar and unexpected-opposite conditions, respectively). The pattern of “benefits” and “costs” of attentional expectancy found by Posner and Snyder for “same” responses was replicated: Subjects were faster and more accurate in the expected condition than in the neutral (uninformative warning signal) condition, but slower and less accurate in the unexpected conditions. Present theoretical interest concerns “same” response times and accuracy for the two unexpected conditions. Under instructions emphasizing accuracy as well as speed (Experiments 1 and 2), performance was worse in the unexpected-similar condition than in the unexpected-opposite condition. Only when instructions deemphasized accuracy (Experiment 2) was performance better in the unexpected-similar condition than in the unexpected-opposite condition. The fact that subjects may have more difficulty switching attention within a category than between categories (at least when instructions emphasize accuracy as well as speed) contrasts sharply with current theoretical emphasis on intracategorical facilitation effects in the priming paradigm. The results are interpreted within the framework of a model of attention (Keele & Neill, 1978) in which the activation of associates to the focus of attention is actively and optionally suppressed so as to reduce present or potential interference with the focal information processing.     

Divided attention: Storing and classifying briefly presented objects

Although in many studies divided attention has been examined by having people perform the same task (e.g., report or search) with a large number of objects, in few studies have people had to perform two logically independent tasks involving the same brief display. In two experiments, subjects saw 200-msec arrays of characters. In dual-task blocks, theyclassified the color of some or all of the items (making an immediate response) andstored the shape of some of the items for a later recognition test. There was not much mutual interference between classifying and storing per se. However, the tasks were by no means independent: there was substantial interference whendifferent objects from the array had to be stored for one task and classified for the other. The results confirm that wholly unrelated visual tasks depend on the same input-attention system and suggest that attending to an object for any purpose may entail storing a representation of it in visual short-term memory.     

Context-specific prospective-memory processing: Evidence for flexible attention allocation adjustments after intention encoding

Prospective memory (PM) is remembering to fulfill intentions in the future. Interference of unfulfilled intentions with ongoing activities reflects the allocation of attention to the PM task. Prior research has shown that, when people know in which specific context PM cues will occur, attention allocation is adaptive, with slower responses in the PM-relevant context. We examined whether people flexibly adjust their attention allocation when the PM–context association is unknown at intention encoding and must be learned on-task. Different stimulus shapes represented contexts in an ongoing task, with PM cues only occurring in trials with one specific shape. Participants informed about the PM-relevant shape responded more slowly on trials with this shape. Participants instructed that only one, unspecified shape was PM-relevant learned the PM–context association and also allocated attention flexibly, depending on context relevance. However, participants with no context-related information at intention encoding failed to learn the PM–context association, resulting in inflexible attention allocation and poorer PM performance. The present study provides evidence that people can flexibly update their attention-allocation policy, and thereby optimize their PM performance after initial intention encoding, but self-guided learning of intention–context associations appears to be limited.     

Effects of songs with prosocial lyrics on prosocial thoughts, affect, and behavior

Previous research has shown that exposure to violent media increased aggression-related affect and thoughts, physiological arousal, and aggressive behavior as well as decreased prosocial tendencies. The present research examined the hypothesis that exposure to prosocial media promotes prosocial outcomes. Three studies revealed that listening to songs with prosocial (relative to neutral) lyrics increased the accessibility of prosocial thoughts, led to more interpersonal empathy, and fostered helping behavior. These results provide first evidence for the predictive validity of the General Learning Model [Buckley, K. E., & Anderson, C. A. (2006). A theoretical model of the effects and consequences of playing video games. In P. Vorderer, & J. Bryant, (Eds.), Playing video games: Motives responses and consequences (pp. 363-378). Mahwah, NJ: Lawrence Erlbaum Associates] for the effects of media with prosocial content on prosocial thought, feeling, and behavior.     

Exposure to violent media: the effects of songs with violent lyrics on aggressive thoughts and feelings

Five experiments examined effects of songs with violent lyrics on aggressive thoughts and hostile feelings. Experiments 1, 3, 4 and 5 demonstrated that college students who heard a violent song felt more hostile than those who heard a similar but nonviolent song. Experiments 2-5 demonstrated a similar increase in aggressive thoughts. These effects replicated across songs and song types (e.g., rock, humorous, nonhumorous). Experiments 3-5 also demonstrated that trait hostility was positively related to state hostility but did not moderate the song lyric effects. Discussion centers on the potential role of lyric content on aggression in short-term settings, relation to catharsis and other media violence domains, development of aggressive personality, differences between long-term and short-term effects, and possible mitigating factors.     

Dividing attention between color and shape: Evidence of coactivation

When attention is divided between spatially distinct objects, the time-to detect a target decreases when two or more targets are present. This redundancy gain can be accounted for by an interactive race model (Mordkoff & Yantis, 1991) in which separate decisions are made about each object, but environmental contingencies among the objects can influence decision times. In the present study, we examined whether the model also accounts for performance when attention must be divided between stimulus attributes other than spatial location. Subjects made target-present responses when displays included a prespecified color, a prespecified letter, or both target features. The data violated the predictions of all separate-activations models, including the interactive race model. Two control experiments ruled out an alternative account based on task complexity. We conclude that coactivation occurs when target attributes from two separable dimensions are simultaneously present, but not when target attributes come from the same dimension. A modular hybrid of race and coactivation models is tentatively proposed.     

Evidence against independent processing of black and white pattern features

Following adaptation to a rectangular grating, subjects observed a shift in the perceived duty cycle of a test grating (Burton, Nagshineh, & Ruddock, 1977; DeValois, 1977). This suggests that size information about black and white pattern components may be analyzed independently. We have tested this hypothesis by combining adaptation to a 2-cpd rectangular wave grating (narrow white bars and wide black bars or vice versa) with adaptation to a 4-cpd sine wave (narrow white and black bars. The data do not support the independent analysis of white and black components, but they may be accounted for by mechanisms sensitive to the relative phase relations among the spatial frequency components of the input.     

Sentence processing: Evidence against the serial,independent stage assumption

The assumption that the processing stages involved in sentence comprehension are serially and independently executed was tested in two separate experiments using two new sentence types. One experiment was a sentence-picture verification task, the other was not. In Experiment I, subjects viewed sentences such as It's false that the dots are red and indicated, by pressing the appropriate response key, which of two colors would make the sentence true. In Experiment II, subjects verified sentences such as It isn't true that the dots aren't red against pictures of colored dots. On the strength of Sternberg's additive factor method, present findings challenge the validity of the serial, independent stage assumption, and results are alternatively discussed in terms of a capacity sharing model.This research was supported by PHS research grant MH 23401 to Sam Glucksberg, principal investigator.     

Divided attention years after severe closed head injury: the effect of dependencies between the subtasks

Lesions of white matter which connects distant brain areas are characteristic for closed head injury (CHI). It was predicted that this impairs divided attention only if dependent subtasks are used which require communication between corresponding brain processes. Fourteen chronic severe CHI patients (mean age 42 years) and 14 healthy controls, matched on age, gender, and education, participated in an experiment on divided attention. A typical left hemisphere task and a typical right hemisphere task must be simultaneously performed in a condition where they are completely independent and in conditions with dependencies between the tasks. Only in the dependent conditions the CHI group showed poor divided attention performance.     

Sing that tune: Infants’ perception of melody and lyrics and the facilitation of phonetic recognition in songs

To better understand how infants process complex auditory input, this study investigated whether 11-month-old infants perceive the pitch (melodic) or the phonetic (lyric) components within songs as more salient, and whether melody facilitates phonetic recognition. Using a preferential looking paradigm, uni-dimensional and multi-dimensional songs were tested; either the pitch or syllable order of the stimuli varied. As a group, infants detected a change in pitch order in a 4-note sequence when the syllables were redundant (experiment 1), but did not detect the identical pitch change with variegated syllables (experiment 2). Infants were better able to detect a change in syllable order in a sung sequence (experiment 2) than the identical syllable change in a spoken sequence (experiment 1). These results suggest that by 11 months, infants cannot “ignore” phonetic information in the context of perceptually salient pitch variation. Moreover, the increased phonetic recognition in song contexts mirrors findings that demonstrate advantages of infant-directed speech. Findings are discussed in terms of how stimulus complexity interacts with the perception of sung speech in infancy.