Tonal hierarchy representations in auditory imagery

Two experiments investigated psychological representations of musical tonality in auditory imagery. In Experiment 1, musically trained participants heard a single tone as a perceptual cue and built an auditory image of a specified major tonality based on that cue; participants’ images were then assessed using judgments of probe tones. In Experiment 2 participants imaged a minor tonality rather than a major one. Analysis of the probe tone ratings indicated that participants successfully imaged both major and minor tonal hierarchies, demonstrating that auditory imagery functions comparably to auditory perception. In addition, the strength of the major tonal image was dependent upon the pitch and tonal relations of the perceptual cue and the to-be-imaged tonality. Finally, representations of minor tonal hierarchies were less robust than those of major ones, converging with perceptual evidence that minor tonalities are less psychologically stable than major tonalities.     

Mental imagery and fiction

Fictions evoke imagery, and their value consists partly in that achievement. This paper offers analysis of this neglected topic. Section 2 identifies relevant philosophical background. Section 3 offers a working definition of imagery. Section 4 identifies empirical work on visual imagery. Sections 5 and 6 criticize imagery essentialism, through the lens of genuine fictional narratives. This outcome, though, is not wholly critical. The expressed spirit of imagery essentialism is to encourage philosophers to ‘put the image back into the imagination’. The weakened conclusion is that while an image is not essential to imagining, it should be returned to our theories of imagination.     

Spontaneous imagery scanning in mental extrapolation

We report an experiment that suggests a functional application of mental-image scanning. After subjects inspected a simple dot pattern, the pattern was removed, and they were then shown an arrow at an unexpected location. Their task was to judge as quickly as possible whether the arrow pointed at any of the dots in the previously observed pattern. Although the subjects were never instructed to form or scan mental images, most of them reported having done so in order to make their judgments, and their reaction times were directly proportional to the distances separating the dots and the arrows, as typically found in image-scanning experiments. Imagery scanning may therefore serve a useful function when one must judge spatial relations between the positions of remembered objects and newly specified locations.     

The role of loudness in auditory imagery

Four experiments studied characteristics of auditory images initiated by named but unheard sounds. The sounds varied in their loudness ratings. As the difference between the loudness ratings of the two sound phrases increased, the times to mentally equate the loudness of the two images increased, whereas the times to identify the louder (or softer) of the images decreased. Moreover, congruity effects were found in the comparative judgment task: Times were faster to identify the louder of two loud-rated stimuli than to judge the softer of the same two stimuli, and times were faster to identify the softer of the two soft-rated than two loud-rated stimuli. The loudness ratings did not always influence performance, however, for neither an image generation nor a reading task showed response times that varied with loudness ratings. These results suggest that sensory/perceptual components are optionally represented in auditory images. These components are included when appropriate to a given task. A control experiment showed that the results cannot be considered epiphenomenal.     

Mental imagery and pictorial memory

Previous research has failed to show consistent effects upon memory performance of individual differences in the use of mental imagery. A test of pictorial memory was devised which varied the ease with which the stimulus patterns could be verbally encoded. A factor analysis related performance in this task to a variety of other individual characteristics. The recall of material which could not be readily verbalized defined a factor within the solution which showed significant loadings of age and performance in the Progressive Matrices, but not of subjective ratings of the vividness of experienced imagery. The recall of material which could be readily verbalized did not contribute to the factorial structure of the results. It was concluded that the two sorts of pictorial material are remembered in quite different ways.     

Perceptual interference and facilitation with auditory imagery

It has been claimed both that (1) imagery selectivelyinterferes with perception (because images can be confused with similar stimuli) and that (2) imagery selectivelyfacilitates perception (because images recruit attention for similar stimuli). However, the evidence for these claims can be accounted for without postulating either image-caused confusions or attentional set. Interference could be caused by general and modality-specific capacity demands of imaging, and facilitation, by image-caused eye fixations. The experiment reported here simultaneously tested these two apparently conflicting claims about the effect of imagery on perception in a way that rules out these alternative explanations. Subjects participated in a two-alternative forced-choice auditory signal detection task in which the target signal was either the same frequency as an auditory image or a different frequency. The possible effects of confusion and attention were separated by varying the temporal relationship between the image and the observation intervals, since an image can only be confused with a simultaneous signal. We found selective facilitation (lower thresholds) for signals of the same frequency as the image relative to signals of a different frequency, implying attention recruitment; we found no selective interference, implying the absence of confusion. These results also imply that frequency information is represented in images in a form that can interact with perceptual representations.     

Mental imagery and the third dimension

What sort of medium underlies imagery for three-dimensional scenes? In the present investigation, the time subjects took to scan between objects in a mental image was used to infer the sorts of geometric information that images preserve. Subjects studied an open box in which five objects were suspended, and learned to imagine this display with their eyes closed. In the first experiment, subjects scanned by tracking an imaginary point moving in a straight line between the imagined objects. Scanning times increased linearly with increasing distance between objects in three dimensions. Therefore metric 3-D information must be preserved in images, and images cannot simply be 2-D "snapshots." In a second experiment, subjects scanned across the image by "sighting" objects through an imaginary rifle sight. Here scanning times were found to increase linearly with the two-dimensional separations between objects as they appeared from the original viewing angle. Therefore metric 2-D distance information in the original perspective view must be preserved in images, and images cannot simply be 3-D "scale-models" that are assessed from any and all directions at once. In a third experiment, subjects mentally rotated the display 90 degrees and scanned between objects as they appeared in this new perspective view by tracking an imaginary rifle signt, as before. Scanning times increased linearly with the two-dimensional separations between objects as they would appear from the new relative viewing perspective. Therefore images can display metric 2-D distance information in a perspective view never actually experiences, so mental images cannot simply be "snapshot plus scale model" pairs. These results can be explained by a model in which the three-dimensional structure of objects is encoded in long-term memory in 3-D object-centered coordinate systems. When these objects are imagined, this information is then mapped onto a single 2-D "surface display" in which the perspective properties specific to a given viewing angle can be depicted. In a set of perceptual control experiments, subjects scanned a visible display by (a) simply moving their eyes from one object to another, (b) sweeping an imaginary rifle sight over the display, or (c) tracking an imaginary point moving from one object to another. Eye-movement times varied linearly with 2-D interobject distance, as did time to scan with an imaginary rifle sight; time to tract a point varied independently with the 3-D and 2-D interobject distances. These results are compared with the analogous image scanning results to argue that imagery and perception share some representational structures but that mental image scanning is a process distinct from eye movements or eye-movement commands.     

Experience with songs in adulthood reduces song-induced gene expression in songbird auditory forebrain

Male songbirds learn to produce song within a limited phase early in life; however they continue to learn to recognize songs in adulthood. Studies looking at Zenk activation after exposure to songs learned early in life for song production and songs learned in adulthood show opposite patterns of activation, suggesting distinct neural mechanisms may be involved in these two forms of learning. In this study, we look at IEG Zenk activation in auditory regions NCM and CMM of song sparrows (Melospiza melodia) to see whether recent exposure to song in adulthood leads to greater or decreased Zenk activation upon hearing that song versus a novel song. We found significantly lower activation in birds exposed to previously heard songs versus novel songs in vNCM but not dNCM, though further analysis suggest an overall trend in NCM. We found no significant difference in the amount of activation to previously heard songs vs. novel songs in CMM. These results support previous findings suggesting that activation is reduced to learned stimuli; we discuss possible implications of these findings in relation to song production learning early in life and song recognition learning in adulthood.     

Mental imagery: in search of a theory

It is generally accepted that there is something special about reasoning by using mental images. The question of how it is special, however, has never been satisfactorily spelled out, despite more than thirty years of research in the post-behaviorist tradition. This article considers some of the general motivation for the assumption that entertaining mental images involves inspecting a picture-like object. It sets out a distinction between phenomena attributable to the nature of mind to what is called the cognitive architecture, and ones that are attributable to tacit knowledge used to simulate what would happen in a visual situation. With this distinction in mind, the paper then considers in detail the widely held assumption that in some important sense images are spatially displayed or are depictive, and that examining images uses the same mechanisms that are deployed in visual perception. I argue that the assumption of the spatial or depictive nature of images is only explanatory if taken literally, as a claim about how images are physically instantiated in the brain, and that the literal view fails for a number of empirical reasons--for example, because of the cognitive penetrability of the phenomena cited in its favor. Similarly, while it is arguably the case that imagery and vision involve some of the same mechanisms, this tells us very little about the nature of mental imagery and does not support claims about the pictorial nature of mental images. Finally, I consider whether recent neuroscience evidence clarifies the debate over the nature of mental images. I claim that when such questions as whether images are depictive or spatial are formulated more clearly, the evidence does not provide support for the picture-theory over a symbol-structure theory of mental imagery. Even if all the empirical claims were true, they do not warrant the conclusion that many people have drawn from them: that mental images are depictive or are displayed in some (possibly cortical) space. Such a conclusion is incompatible with what is known about how images function in thought. We are then left with the provisional counterintuitive conclusion that the available evidence does not support rejection of what I call the "null hypothesis"; namely, that reasoning with mental images involves the same form of representation and the same processes as that of reasoning in general, except that the content or subject matter of thoughts experienced as images includes information about how things would look.     

Mental imagery, reasoning, and blindness

Although reasoning seems to be inextricably linked to seeing in the “mind's eye”, the evidence is equivocal. In three experiments, sighted, blindfolded sighted, and congenitally totally blind persons solved deductive inferences based on three sorts of relation: (a) visuo-spatial relations that are easy to envisage either visually or spatially, (b) visual relations that are easy to envisage visually but hard to envisage spatially, and (c) control relations that are hard to envisage both visually and spatially. In absolute terms, congenitally totally blind persons performed less accurately and more slowly than the sighted on all such tasks. In relative terms, however, the visual relations in comparison with control relations impeded the reasoning of sighted and blindfolded participants, whereas congenitally totally blind participants performed the same with the different sorts of relation. We conclude that mental images containing visual details that are irrelevant to an inference can even impede the process of reasoning. Persons who are blind from birth—and who thus do not tend to construct visual mental images—are immune to this visual-impedance effect.     

Mental imagery,reasoning, and blindness

Although reasoning seems to be inextricably linked to seeing in the “mind's eye”, the evidence is equivocal. In three experiments, sighted, blindfolded sighted, and congenitally totally blind persons solved deductive inferences based on three sorts of relation: (a) visuo-spatial relations that are easy to envisage either visually or spatially, (b) visual relations that are easy to envisage visually but hard to envisage spatially, and (c) control relations that are hard to envisage both visually and spatially. In absolute terms, congenitally totally blind persons performed less accurately and more slowly than the sighted on all such tasks. In relative terms, however, the visual relations in comparison with control relations impeded the reasoning of sighted and blindfolded participants, whereas congenitally totally blind participants performed the same with the different sorts of relation. We conclude that mental images containing visual details that are irrelevant to an inference can even impede the process of reasoning. Persons who are blind from birth—and who thus do not tend to construct visual mental images—are immune to this visual-impedance effect.     

Mental effort and task interference in auditory attention

Dual-task performance was examined in three experiments. The primary task was to repeat or to add one to four digits presented auditorily at a rate of 1 digit/second. This primary task was combined with three different secondary tasks in which subjects listened to a list of words either for later recognition of some of the words (Experiment 1) or for detection and a later report of a target word (Experiments 2 and 3). Different patterns of task interference were obtained. Recognition performance was sensitive to between-task variations in capacity demands but did not reflect momentary attentional demands within the primary task. Detection performance reflected both between-task and within-task variation in capacity demands of the primary task. The interference between the primary and the secondary task was mutual, with more interference when the selection-cue in the detection task was a category name than when it was the target word itself. These findings are discussed in terms of effort theory of attention and the role of attentional strategies in dual-task performance.     

Reading voices and hearing text: talker-specific auditory imagery in reading

A series of experiments was conducted to determine if linguistic representations accessed during reading include auditory imagery for characteristics of a talker's voice. In 3 experiments, participants were familiarized with two talkers during a brief prerecorded conversation. One talker spoke at a fast speaking rate, and one spoke at a slow speaking rate. Each talker was identified by name. At test, participants were asked to either read aloud (Experiment 1) or silently (Experiments 1, 2, and 3) a passage that they were told was written by either the fast or the slow talker. Reading times, both silent and aloud, were significantly slower when participants thought they were reading a passage written by the slow talker than when reading a passage written by the fast talker. Reading times differed as a function of passage author more for difficult than for easy texts, and individual differences in general auditory imagery ability were related to reading times. These results suggest that readers engage in a type of auditory imagery while reading that preserves the perceptual details of an author's voice.     

Parallel scanning of auditory and visual information

Two experiments involving memory retrieval of auditorilv and visually presented materials were performed. In Experiment I, subjects were presented with memory sets of 1, 2, or 4 stimuli and then with a test item to be classified as belonging or not belonging to the memory set. In Condition 1, each memory stimulus was a single, auditorily presented letter. In Condition 2, each memory stimulus was a visually presented letter. In Conditions 3 and 4, each memory stimulus was a pair of letters, one presented visually and the other auditorily. Mean reaction time (RT) for the classification task increased as a function of number of memory stimuli at equal rates for all four conditions. This was interpreted as evidence for a parallel scanning process in Conditions 3 and 4 where the auditory item and visual item of each memory stimulus pair can be scanned simultaneously. Experiment II compared memory retrieval for a simultaneous condition in which auditory and visual memory items were presented as pairs with a sequential condition in which mixed auditory-visual memory sets were presented one item at a time. RTs were shorter for the simultaneous condition. This was interpreted as evidence that parallel scanning may depend upon memory input parameters.     

Mental imagery combined with physical practice of approach shots for golf beginners

Recent research on motor skills of golf have pointed to the usefulness of mental imagery. In golf, such training is rarely used as a teaching technique for beginners on the grounds that only top professionals stand to gain from mental imagery. This study tested whether mental imagery combined with physical practice can improve golf performance for the approach shot. 23 volunteer beginners, 8 women and 15 men, M age 23.4 yr. (SD = 3.7), enrolled in the University Physical and Sporting Activities Department, were divided into three groups, using a combination of physical practice of the approach shot plus mental imagery, physical practice only, and a third group engaging in various sporting activities instead of either mental or physical practice of the chip shot. Analysis showed that the beginners' approach shot performance improved most in the group combining physical practice and mental imagery when compared with the group just physically practising the approach shot. It seems mental training can be used effectively to improve performance even with beginners.     

Mental imagery and chunks: Empirical and computational findings

To investigate experts' imagery in chess, players were required to recall briefly presented positions in which pieces were placed on the intersections between squares (intersection positions). Position types ranged from game positions to positions in which both the piece distribution and the location were randomized. Simulations were run with the CHREST model (Gobet & Simon, 2000). The simulations assumed that pieces had to be centered back, one by one, to the middle of the squares in the mind's eye before chunks could be recognized. Consistent with CHREST's predictions, chess players (N = 36), ranging from weak amateurs to grandmasters, exhibited much poorer recall for intersection positions than for standard positions (pieces placed on the centers of the squares). For the intersection positions, the skill difference in recall was larger for game positions than for the randomized positions. The participants recalled bishops better than they recalled knights, suggesting that Stroop-like interference impairs recall of the latter. The data supported both the time parameter in CHREST for shifting pieces in the mind's eye (125 msec per piece) and the seriality assumption. In general, the study reinforces the plausibility of CHREST as a model of cognition.     

Developmental aspects of auditory and visual scanning.

60 Ss from Grades 1 through 6 were administered an auditory and visual scanning procedure and 27 of those Ss were given arithmetic and reading achievement tests. Data indicated scanning ability increases linearly with grade in school and the relationship between the scanning measures also increases sharply with grade. Auditory scanning was related to academic achievement; visual scanning only approached significance with arithmetic achievement but was unrelated to reading achievement.