The Two Faces of Mental Imagery

Mental imagery has often been taken to be equivalent to “sensory imagination”, the perception-like type of imagination at play when, for example, one visually imagines a flower when none is there, or auditorily imagines a music passage while wearing earplugs. I contend that the equation of mental imagery with sensory imagination stems from a confusion between two senses of mental imagery. In the first sense, mental imagery is used to refer to a psychological attitude, which is perception-like in nature. In the second sense, mental imagery refers to a mental content, which can be grasped via different attitudes. I will show that failure to acknowledge the distinction between these senses of mental imagery has muddled philosophical discussion. This distinction brings much needed clarity to debates where sensory imagination and mental imagery are invoked, shedding light on issues such as the nature of imagistic mental states, and the representational powers and limits of mental imagery. I will conclude by sketching a general attitudinal account of imagination that does justice to both senses of mental imagery, outlining a promising framework for understanding imagination.     

基于fNIRS的运动执行与运动想象脑激活模式比较

使用《运动想象问卷−修订版》筛选出的30名被试(男女各半), 采用功能性近红外光谱成像技术(fNIRS)监测被试在执行实际举哑铃(男生, 4磅和8磅; 女生, 2磅和4磅)任务和想象举同等重量哑铃任务时, 其大脑皮层氧合血红蛋白浓度的变化。结果发现：男女被试在运动执行与运动想象任务下都激活了主运动皮层; 且运动执行的大脑激活水平高于运动想象。在执行实际运动任务时, 运动强度显著影响大脑皮层血氧浓度的变化, 表现出左半球偏侧化优势; 在执行想象运动任务时, 运动强度没有影响大脑皮层血氧浓度的变化, 且无偏侧化现象。     

SHAPING YOUR OWN LIFE

Abstract: A distinction is made between imagination in the narrow sense and in the broad sense. Narrow imagination is characterised as the ability to “see” pictures in the mind's eye or to “hear” melodies in the head. Broad imagination is taken to be the faculty of creating, either in the strict sense of making something ex nihilo or in the looser sense of seeing patterns in some data. The article focuses on a particular sort of broad imagination, the kind that has to do with creating, not a work of art, a scientific theory or a political vision but one's own life. We shape our lives through our actions, and these actions not only influence our future—a commonplace—but also determine our past, which is a new and more controversial perspective.     

When music tempo affects the temporal congruence between physical practice and motor imagery

When people listen to music, they hear beat and a metrical structure in the rhythm; these perceived patterns enable coordination with the music. A clear correspondence between the tempo of actual movement (e.g., walking) and that of music has been demonstrated, but whether similar coordination occurs during motor imagery is unknown. Twenty participants walked naturally for 8 m, either physically or mentally, while listening to slow and fast music, or not listening to anything at all (control condition). Executed and imagined walking times were recorded to assess the temporal congruence between physical practice (PP) and motor imagery (MI). Results showed a difference when comparing slow and fast time conditions, but each of these durations did not differ from soundless condition times, hence showing that body movement may not necessarily change in order to synchronize with music. However, the main finding revealed that the ability to achieve temporal congruence between PP and MI times was altered when listening to either slow or fast music. These data suggest that when physical movement is modulated with respect to the musical tempo, the MI efficacy of the corresponding movement may be affected by the rhythm of the music. Practical applications in sport are discussed as athletes frequently listen to music before competing while they mentally practice their movements to be performed.     

Imagery of errors in typing

Using a typing task we investigated whether insufficient imagination of errors and error corrections is related to duration differences between execution and imagination. In Experiment 1 spontaneous error imagination was investigated, whereas in Experiment 2 participants were specifically instructed to imagine errors. Further, in Experiment 2 we manipulated correction instructions (whether or not to correct errors) and controlled for visual feedback in executed typing (letters appearing on the screen or not). Participants executed and imagined typing proverbs of different lengths. Errors and error corrections explained a significant amount of variance of execution minus imagination differences in Experiment 1, and in Experiment 2 when participants were instructed to correct errors, but not when participants were instructed not to correct errors. In Experiment 2 participants corrected and reported more errors with than without visual feedback. However, the relation between execution − imagination duration differences and errors and error corrections was unaffected by visual feedback. The types of errors reported less often in imagination than in execution were related to processes in typing execution. We conclude that errors and error corrections are not spontaneously imagined during motor imagery, and that even when attention is drawn to their occurrence only some are imagined. This may be due to forward models not predicting all aspects of an action, imprecise forward models, or a neglect of monitoring error signals during motor imagery.     

The Sounds of Sentences: Differentiating the Influence of Physical Sound,Sound Imagery,and Linguistically Implied Sounds on Physical Sound Processing

Both the imagery literature and grounded models of language comprehension emphasize the tight coupling of high-level cognitive processes, such as forming a mental image of something or language understanding, and low-level sensorimotor processes in the brain. In an electrophysiological study, imagery and language processes were directly compared and the sensory associations of processing linguistically implied sounds or imagined sounds were investigated. Participants read sentences describing auditory events (e.g., “The dog barks”), heard a physical (environmental) sound, or had to imagine such a sound. We examined the influence of the 3 sound conditions (linguistic, physical, imagery) on subsequent physical sound processing. Event-related potential (ERP) difference waveforms indicated that in all 3 conditions, prime compatibility influenced physical sound processing. The earliest compatibility effect was observed in the physical condition, starting in the 80–110 ms time interval with a negative maximum over occipital electrode sites. In contrast, the linguistic and the imagery condition elicited compatibility effects starting in the 180–220 ms time window with a maximum over central electrode sites. In line with the ERPs, the analysis of the oscillatory activity showed that compatibility influenced early theta and alpha band power changes in the physical, but not in the linguistic and imagery, condition. These dissociations were further confirmed by dipole localization results showing a clear separation between the source of the compatibility effect in the physical sound condition (superior temporal area) and the source of the compatibility effect triggered by the linguistically implied sounds or the imagined sounds (inferior temporal area). Implications for grounded models of language understanding are discussed.     

Seeing what they read and hearing what they say: Readers’ representation of the story characters’ world

Do readers “see” the words that story characters read and “hear” the words that they hear? Just as priming effects are reduced when stimuli are presented cross-modally on two different occasions, we found reduced transfer effects when story characters were described as experiencing stimuli cross-modally. In Experiment 1, a repeated phrase was described as being part of a spoken message in both Story A and Story B, and transfer effects were found. In Experiment 2, in contrast, when the phrase was described as a written note in one story and a spoken message in the other, reading-time results indicated that readers did not retrieve the meaning of the repeated phrase. The results are consistent with findings indicating that visual imagery simulates visual processing and that auditory imagery simulates auditory processing. We conclude that readers mentally simulate the perceptual details involved in story characters’ linguistic exchanges.     

Tool characteristics in imagery of tool actions

Are tool characteristics represented in imagined tool actions? In two experiments participants imagined and executed coloring rectangles with a thick and a thin pen. In Experiment 2, an additional execution condition without visual feedback of coloring allowed us to dissociate between the relevance of kinesthetic and visual feedback. Pen thickness influenced coloring durations in all conditions, indicating that characteristics of a simple tool are represented during imagery. Imagination was shorter than execution, indicating that imagination may be less detailed than execution. Execution without visual feedback was even shorter than imagination, indicating that vision is more important than kinesthesis for differences between imagination and execution, and that either imagining the movement, inhibiting movement execution or imagining the progress of the action is effortful during imagery. In conclusion, characteristics of simple tools are represented in imagined tool actions but the representation of tools’ effects may not always be adequate.     

Individual differences in imagination inflation

Garry, Manning, Loftus, and Sherman (1996) found that when adult subjects imagined childhood events, these events were subsequentlyjudged as more likely to have occurred than were not-imagined events. The authors termed this effect imagination inflation. We replicated the effect, using a novel set of Life Events Inventory events. Further, we tested whether the effect is related to four subject characteristics possibly associated with false memory creation. The extent to which subjects inflated judged likelihood following imagined events was associated with indices of hypnotic suggestibility and dissociativity, but not with vividness of imagery or interrogative suggestibility. Results suggest that imagination plays a role in subsequent likelihood judgments regarding childhood events, and that some individuals are more likely than others to experience imagination inflation.     

Music to the inner ears: Exploring individual differences in musical imagery

In two studies, we explored the frequency and phenomenology of musical imagery. Study 1 used retrospective reports of musical imagery to assess the contribution of individual differences to imagery characteristics. Study 2 used an experience sampling design to assess the phenomenology of musical imagery over the course of one week in a sample of musicians and non-musicians. Both studies found episodes of musical imagery to be common and positive: people rarely wanted such experiences to end and often heard music that was personally meaningful. Several variables predicted musical imagery, including personality, musical preferences, and positive mood. Musicians tended to hear musical imagery more often, but they reported less frequent episodes of deliberately-generated imagery. Taken together, the present research provides new insights into individual differences in musical imagery, and it supports the emerging view that such experiences are common, positive, and more voluntary than previously recognized.     

Phenomenal consciousness in dreams and in mind wandering

Dreaming can be explained as the product of an interaction among memory processes, elaborative processes, and phenomenal awareness. A feedback circuit is activated by this interaction according to the associative links and the requirements of the dream scene. Recently, it has been hypothesized that a partial similarity exists between dreaming and mind wandering and that these two processes may involve the same neural default network. This commentary discusses the differences and similarities between phenomenal consciousness during dreaming and phenomenal consciousness during mind wandering from the perspective of the “continuity” of engagement of cognitive systems. The greatest difference consists in the lack of reality testing during dreaming. Dream imagery is hallucinatory by nature. Consequently, the simulated world in dreams makes dream imagery more akin to perception. In contrast, the imagery of mind wandering is more similar to imagination. The level of meta-awareness is preserved more frequently and to a greater degree in mind wandering.     

Motor imagery in typing: effects of typing style and action familiarity

The influences of typing style and action familiarity on executed and imagined typing were investigated. A group of touch typists and a group of hunt-and-peck typists were asked to imagine and execute typing texts of different lengths in two different styles: with ten fingers (familiar for touch typists, unfamiliar for hunt-and-peck typists) and with two fingers (unfamiliar for touch typists, familiar for hunt-and-peck typists). The imagination (but not the execution) of familiar and unfamiliar typing was correlated in both groups, indicating that participants used skill knowledge from the familiar action to imagine the unfamiliar action. Only when touch typists imagined familiar typing accurate motor imagery was observed (similar durations of and positive correlations between imagination and execution). When touch typists imagined unfamiliar typing, the average imagination durations resembled the execution durations, but correlations indicated individual differences in the processes of imagination and execution. Hunt-and-peck typists showed shorter imagination than execution durations with both familiar and unfamiliar typing, indicating that in both styles they did not imagine all details of typing. Also, they did not imagine some details specifically related to unfamiliar typing (reflected in particularly high percentages of absolute error). However, correlations indicated that individual difficulties in executing the unfamiliar action were reflected in the imagination durations. In conclusion, skill knowledge from familiar actions is used to imagine unfamiliar actions. Familiarity with actions promotes accurate motor imagery, but only if stable internal action representations have been acquired, and not if action control relies on online, step-by-step control. However, stable internal action representations of familiar actions may be detrimental for imagery of unfamiliar actions.     

Perceptual representations in false recognition and priming of pictures

Using a new procedure, we investigate whether imagination can induce false memory by creating a perceptual representation. Participants studied pictures and words with and without an imagery task and at test performed both a direct recognition test and an indirect perceptual identification test on pictorial stimuli. Corrected false recognition rates were 7% for pictures studied in word form (Experiment 1), 26% for pictures imagined once (Experiment 2), and 48% for pictures imagined multiple times (Experiment 3), although on the indirect test, no priming was found for these items. Furthermore, a perceptual/conceptual imagery manipulation did not affect the tendency to claim that imagined items had been studied as pictures (Experiment 4). These results suggest that the false memories reported on direct tests are not driven by perceptual representations.     

The influence of imagery ability on color aftereffects produced by physically present and imagined induction stimuli

Two methods of induction were used to produce orientation-contingent color aftereffects for observers assigned to one of three groups (high, medium, and low) on the basis of self-rated imagery ability. In Experiment 1, observers were required to make magnitude estimates of color aftereffects following inspection of stimulus patterns normally used to produce McCollough effects (e.g., red vertical contours, green horizontal contours). Experiment 2 was a partial replication of Experiment 1, with additional induction conditions in which observers were required to imagine the presence of appropriately oriented contours when particular homogeneous color patches were presented. The results indicated that self-rated imagery ability was not a significant factor in differentiating between observers’ performance when orthodox induction procedures were used (Experiment 1). In addition, there were no reliable indications (Experiment 2) that imagined stimulus attributes can be effectively substituted for real stimulus attributes in order to produce orientation-contingent color aftereffects. The results are discussed in terms of their implications for the use of imagery-induced perceptual phenomena as a paradigm for investigating the possibility of common neural mechanisms in perception and imagination; in addition, the general implications of the results for understanding the functional significance of self-reported imagery ability are examined.     

Neuro-cognitive aspects of “OM” sound/syllable perception: A functional neuroimaging study

The sound “OM” is believed to bring mental peace and calm. The cortical activation associated with listening to sound “OM” in contrast to similar non-meaningful sound (TOM) and listening to a meaningful Hindi word (AAM) has been investigated using functional magnetic resonance imaging (MRI). The behaviour interleaved gradient technique was employed in order to avoid interference of scanner noise. The results reveal that listening to “OM” sound in contrast to the meaningful Hindi word condition activates areas of bilateral cerebellum, left middle frontal gyrus (dorsolateral middle frontal/BA 9), right precuneus (BA 5) and right supramarginal gyrus (SMG). Listening to “OM” sound in contrast to “non-meaningful” sound condition leads to cortical activation in bilateral middle frontal (BA9), right middle temporal (BA37), right angular gyrus (BA 40), right SMG and right superior middle frontal gyrus (BA 8). The conjunction analysis reveals that the common neural regions activated in listening to “OM” sound during both conditions are middle frontal (left dorsolateral middle frontal cortex) and right SMG. The results correspond to the fact that listening to “OM” sound recruits neural systems implicated in emotional empathy.     

没听到？“听”到！——来自听觉表象神经机制研究的证据

近年来听觉表象开始得到关注,相关研究包括言语声音、音乐声音、环境声音的听觉表象三类。本文梳理了认知神经科学领域对上述三种听觉表象所激活的脑区研究,比较了听觉表象和听觉对应脑区的异同,并展望了听觉表象未来的研究方向。     

Involuntary and voluntary recall of musical memories: A comparison of temporal accuracy and emotional responses

Comparisons between involuntarily and voluntarily retrieved autobiographical memories have revealed similarities in encoding and maintenance, with differences in terms of specificity and emotional responses. Our study extended this research area into the domain of musical memory, which afforded a unique opportunity to compare the same memory as accessed both involuntarily and voluntarily. Specifically, we compared instances of involuntary musical imagery (INMI, or “earworms”)—the spontaneous mental recall and repetition of a tune—to deliberate recall of the same tune as voluntary musical imagery (VMI) in terms of recall accuracy and emotional responses. Twenty participants completed two 3-day tasks. In an INMI task, participants recorded information about INMI episodes as they occurred; in a VMI task, participants were prompted via text message to deliberately imagine each tune they had previously experienced as INMI. In both tasks, tempi of the imagined tunes were recorded by tapping to the musical beat while wearing an accelerometer and additional information (e.g., tune name, emotion ratings) was logged in a diary. Overall, INMI and VMI tempo measurements for the same tune were strongly correlated. Tempo recall for tunes that have definitive, recorded versions was relatively accurate, and tunes that were retrieved deliberately (VMI) were not recalled more accurately in terms of tempo than spontaneous and involuntary instances of imagined music (INMI). Some evidence that INMI elicited stronger emotional responses than VMI was also revealed. These results demonstrate several parallels to previous literature on involuntary memories and add new insights on the phenomenology of INMI.     

初级视觉皮层在表象表征方式研究中的作用

表象的信息表征方式一直是心理学研究的热点问题,脑成像技术在该问题的研究中发挥了巨大作用。本文以初级视觉皮层(V1)在表象表征方式研究中的作用为主线,系统梳理了基于脑成像技术开展的表象实质争论的核心问题,归纳分析了相关争论问题演绎发展的内在逻辑脉络,在此基础上指出了表象研究中需要进一步解决的关键问题,以期能够促进相关研究问题的进一步开展。     

Timing processes in motor imagery

Previous research shows inconsistencies in the timing of imagined and actual actions. Little is known about the timing in imagery, or how it relates to other forms of timing. Two studies examined whether imagery timing followed Weber's law, where variations in judgements grow linearly as the interval duration increases, or Vierordt's law, where short durations are overestimated and longer durations underestimated. In Study 1 participants (n=22) mentally walked and estimated journey times for flat paths and stairways, with and without a load. The timing patterns that emerged did not conform to Weber's law. In Study 2 participants (n=20) completed imagery, reproduction, production, and estimation timing tasks. Timing errors for imagery along a straight path, reproduction, estimation, and production all showed “Vierordt-like” effects. However, when imagining walking in a square participants consistently overestimated. It was concluded that imagery and interval timing processes are similar, but imagery timing is task dependent.