A Review of Contemporary Ideomotor Theory

A Review of Contemporary Ideomotor Theory
Yun Kyoung Shin,Robert W.Proctor,and E.J.Capaldi
Purdue University
A framework for action planning,called ideomotor theory ,suggests that actions are represented by their perceivable effects.Thus,any activation of the effect image,either endogenously or exogenously,will trigger the corresponding action.We review contemporary studies relating to ideomotor theory in which researchers have investigated various manipulations of action effects and how those effects acquire discriminative control over the actions.Evidence indicates that the knowledge about the relation between response and effect is still a critical component even when other factors,such as stimulus–response or response–response relations,are controlled.When consistent tone effects are provided after responses are made,performance in serial-reaction tasks is better than when the effects are random.Methodology in which acquisition and test stages are used with choice–reaction tasks shows that an action is automat-ically associated with its effect bilaterally and that anticipation of the effect facilitates action.Ideomotor phenomena include stimulus–response compatibility,in which the perceptual feature of the stimulus activates its corresponding action code when the stimulus itself resembles the effect codes.For this reason,other stimulus-driven action facilitation such as ideomotor action and imitation are treated as ideomotor phenomena and are reviewed.Ideomotor theory also implies that ongoing action affects perception of concurrent events,a topic which we review briefly.Issues concerning ideomotor theory are identified and evaluated.We categorize the range of ideomotor explanations into several groups by whether intermediate steps are assumed to complete sensorimotor transformation or not and by whether a general theoretical framework or a more restricted one is provided by the account.
Keywords:ideomotor theory,motor control,action planning,common coding,response–effect association
An approach to perception–action relations called ideomotor theory originated in the 19th century along two roots (Stock &Stock,2004):those of the German philosophers Herbart (1816,1825),Lotze (1852),and Harless (1861)and those of the British physiologists Laycock (1845)and Carpenter (1852).Various ver-sions of ideomotor theory have been promulgated,but the idea behind them all is that internal images of actions and the actions themselves are tightly linked or that perceptual events tend to generate actions for which the feedback is similar.James (1890/1950)emphasized ideomotor theory and brought it to the attention of many psychologists.With the advent of behaviorism,ideomotor theory fell into disfavor due to challenges posed by Thorndike (1913)and others.The first modern statement of ideomotor theory was that of Greenwald (1970),who published studies on what he called the ideomotor principle .Also in the early 1970s,some animal learning researchers began to incorporate the concept of action effect in their theories (e.g.,Bolles,1972).However,wide-spread interest in ideomotor theory did not occur until later,
starting with a chapter by Prinz (1987).Since then,there has been increasing effort devoted to developing ideomotor theory and conducting experiments related to the principle.
Stock and Stock (2004)reviewed the history of ideomotor theory up to the middle of the 20th century.The present article is intended as a complement to their article;in it,we review and evaluate contemporary work on ideomotor theory from that time to the present.After describing use of the term ideomotor ,we briefly discuss the early views of ideomotor theory.In the remainder of the article,we review contemporary research.
Use of the Term Ideomotor
As of Week 1of February 2010,PsycINFO listed 134entries with ideomotor/ideo-motor in the title and 517results with it as keyword.About 60%of those entries are related to the study of ideomotor apraxia ,a neurological disorder characterized by an inability to translate an idea into voluntary movement (Rothi &Ochipa,1991).In other entries,the term ideomotor/ideo-motor is used in various contexts,with the concept loosely defined.Ideo-motor action narrowly indicates movements that arise in individ-uals while they observe actions of others (e.g.,Knuf,Aschersle-ben,&Prinz,2001)or action control guided by an anticipatory representation of the action’s sensory feedback (e.g.,Elsner &Hommel,2001).Several investigators have also studied ideomotor (IM)-compatible tasks for which the response feedback resembles the stimulus (e.g.,Greenwald &Shulman,1973).The following are examples of use of the term ideomotor :
This article was published Online First September 6,2010.
Yun Kyoung Shin,Robert W.Proctor,and E.J.Capaldi,Department of Psychological Sciences,Purdue University.
Robert W.Proctor’s work on the article was supported in part by Army Research Office Multidisciplinary University Research Initiative Grant W911NF-05-1-0153.
Correspondence concerning this article should be addressed to Yun Kyoung Shin,Department of Psychological Sciences,Purdue University,West Lafayette,IN 47907-1364.E-mail:ykshin@
Psychological Bulletin
©2010American Psychological Association 2010,Vol.136,No.6,943–9740033-2909/10/$12.00DOI:10.1037/a0020541
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T h i s d o c u m e n t i s c o p y r i g h t e d b y t h e A m e r i c a n P s y c h o l o g i c a l A s s o c i a t i o n o r o n e o f i t s a l l i e d p u b l i s h e r s . T h i s a r t i c l e i s i n t e n d e d s o l e l y f o r t h e p e r s o n a l u s e o f t h e i n d i v i d u a l u s e r a n d i s n o t t o b e d i s s e m i n a t e d b r o a d l y .
•“The term ideomotor action denotes body movements that tend to arise in observers watching other people perform certain actions”(Knuf et al.,2001,p.779).
•“The term ideo-motor action has been used to refer to move-ments that are performed in accordance with movements that are perceived—i.e.,to situations where action is (seems to be)imme-diately guided by perception”(Prinz,1987,p.47).
•“In terms of IM [ideomotor]theory,the response code is directly activated by signals that closely resemble sensory feed-back from the response.A relationship between stimulus and response of IM compatibility is defined,then,as one in which the stimulus resembles sensory feedback from the response”(Green-wald &Shulman,1973,p.70).
•“The feedback of the button-pressing response does not totally resemble the vibration stimulation and the ideomotor compatibility is relatively low”(ten Hoopen,Akerboom,&Raaymakers,1982,p.156).
Ideomotor comes from the Greek word idea ,meaning form ,and the Latin word motare ,meaning to move about ,and is defined by Merriam-Webster’s Online Dictionary as “not reflex but motivated by an idea”(“Ideomotor,”n.d.).Most of the ideomotor referents indicate phenomena of induced action either endogenously or exogenously.Historically,ideomotor action has referred to sym-pathetic action,which is induced movement evoked by a dynamic visual scene (Knuf et al.,2001;Prinz,1987).Though research has focused mainly on the influence of perceivable environmental change on action,as reflected by use of the more popular term ideomotor action rather than the term ideomotor perception ,the ideomotor approach does not deny the opposite direction of influ-ence on perception while a certain action is being performed.
Historical Background of Ideomotor Action
The term ideomotor action was first coined by Carpenter (1852),who viewed ideomotor action as a “reflex action of the cere-brum ...that manifests itself not only in Psychical change,but also in Muscular movements:and these may ...proceed ...from simple Ideas,without any excitement of Feeling,in which case they may be designated ideo-motor ”(1874,p.105).Carpenter is known for invoking ideomotor action to explain paranormal phe-nomena such as table turning in se ´ances,“magic”movement of a pendulum held by a string,and movement of a divining rod used for dowsing.These reflex actions were considered by him to be most evident for situations in which “the current of thought and feeling flows on under the sole guidance of Suggestion,and without any interference from the Will”(1874,p.105).Carpenter also considered ideomotor action to be involved in many behav-iors,stating,“We may range under the same category all those actions performed by us in our ordinary course of life ,which are rather the automatic expressions of the ideas that may be dominant in our minds at the time,than prompted by distinct volitional efforts”(1874,p.280).According to Carpenter,“In a certain state of mental concentration,the expectation of a result is sufficient to determine—without any voluntary effort,and even in opposition to the Will (for this may be honestly exerted in the attempt to keep the hand perfectly unmoved)—the Muscular movements by which it is produced”(1874,p.287).
Carpenter’s views on ideomotor action were based on those of Laycock (1845),who observed that hydrophobic patients (i.e.,
persons with rabies)reacted physically not only to water itself but also to the idea of water provided through suggestion.From these observations,Laycock concluded that mental images were suffi-cient to initiate actions ycock (1860)treated volun-tary motoric acts in a similar manner,saying,“The intent as to the future ...arises in the consciousness before the state ‘I will’passes into act.This includes two things—a perception of the end,and a desire to attain it”(p.55).
The German philosophers were interested in formulating ideo-motor theory as a general explanation of action control.Herbart’s (1816,1825)views on ideomotor action are especially similar to those of current researchers.He did not restrict ideomotor action to reflexive behavior,and he considered the role of learning in the development of ideomotor codes.According to Herbart,actions are initiated by anticipation or desire of the to-be-produced sensory effects.He proposed a two-step process:(a)automatic association of actions and their sensory effects when they are executed and (b)purposeful use of these associations to initiate actions and bring about the intended action effects.Lotze (1852)and Harless (1861)expanded on Herbart’s views.
James (1890/1950)defined ideomotor action as “the sequence of movement upon the mere thought of it”(p.522),saying,“Whenever movement follows unhesitatingly and immediately the notion of it in the mind,we have ideo-motor action”(p.522).He suggested that the immediate or direct relation between “ideas”and movements is the critical factor to induce a voluntary move-ment by assuming that an action is represented in terms of the sensory form of its effect.According to James (1890/1950,p.526),merely thinking of its effect image will activate the intended motor program:“Every representation of a movement awakens in some degree the actual movement which is its object.”One reason why movements will not occur in all situations is that “the bare pres-ence of another idea will prevent its taking place”(p.527).James attributed development of ideomotor action to the co-occurrence of sensory input and action:“When a sensation has once produced a movement in us,the next time we have the sensation,it tends to suggest the idea of a movement,even before the movement occurs”(p.585).
Stock and Stock (2004)noted that although ideomotor theory fell out of favor early in the 20th century,a few researchers pursued its implications in empirical and theoretical work.We will not review the work that they covered but will describe Hull’s (1931)proposed solution to ideomotor behavior.Hull developed the notion of anticipatory goal reactions,depicted as r G Ϫs G ,which in his theory are representations of the goal reaction (R G )and the resulting proprioceptive stimuli (S G ).He argued against the view that ideas precede and evoke acts.According to Hull:
In contrast to that view,the hypothesis here put forward is (1)that ideo-motor acts are in reality anticipatory goal reactions and,as such,are called into existence by ordinary physical stimulation;and (2)that these anticipatory goal reactions are pure-stimulus acts and,as such,guide and direct the more explicit and instrumental activities of the organism.In short,ideo-motor acts,instead of being evoked by ideas,are ideas.(p.502)
Thus,Hull (1931)emphasized the importance of the goal action and resulting sensory feedback in his explanation of ideomotor behavior.Hull’s analysis was given detailed coverage by Green-wald (1970)in his article that initiated the modern revival of
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T h i s d o c u m e n t i s c o p y r i g h t e d b y t h e A m e r i c a n P s y c h o l o g i c a l A s s o c i a t i o n o r o n e o f i t s a l l i e d p u b l i s h e r s . T h i s a r t i c l e i s i n t e n d e d s o l e l y f o r t h e p e r s o n a l u s e o f t h e i n d i v i d u a l u s e r a n d i s n o t t o b e d i s s e m i n a t e d b r o a d l y .
ideomotor theories of action.Greenwald stated,“The fundamental insight in Hull’s r G Ϫs G analysis was the use of sensory feedback from an anticipated response as a mediator of performance”(p.78).However,Hull’s insight has not been credited in most subse-quent work on the topic.
A Modern Version of Ideomotor Theory:Greenwald’s
(1970)Ideomotor Mechanism
Greenwald’s (1970)analysis of the ideomotor mechanism is generally regarded as a revival of James’s (1890/1950)ideomotor principle and a functional translation of James’s ideas into more verifiable terms (e.g.,Knuf et al.,2001).Greenwald contrasted four different feedback mechanisms mediating voluntary perfor-mance:serial chaining,fractional anticipatory goal response,closed-loop mechanism,and ideomotor mechanism.In all mech-anisms,sensory feedback resulting from self-action is considered a crucial mediator in action control.Greenwald gave “special reference”(p.73)to the ideomotor principle and noted that it is a basic mechanism of voluntary action.
Greenwald (1970)suggested that the idea or image of a response and contiguity of events are sufficient for instrumental condition-ing.According to his description of James’s (1890/1950)deriva-tion of the ideomotor mechanism,there are three significant events 1(see Figure 1):Stimulus (S)–response (R)–effect/sensory feedback (E).
The S,R,and E events unfold in sequence across time,and they are usually contingent or causally related to each other.If an agent generates a certain movement,action-dependent feedback will follow.Unique triplets of S 1–R 1–E 1,S 2–R 2–E 2,...,S n –R n –E n occur repeatedly to an agent.By repeated exposure to the contin-gent triplets,the agent can associate the relationship between events automatically to some degree.This association results in “conditioned anticipatory images of response feedback”(Green-wald,1970,p.85),2denoted by the lowercase letter e n ,in Figure 1.Anticipatory images are conditioned to each contingent forthcom-ing effect and then finally acquire discriminative control over their corresponding responses even without the original stimulus to trigger the responses.Anticipatory associations are chained be-tween the consecutive elements of the effect sequence so that activation of the anticipatory image triggers the anticipation of the next effect to be produced,which in turn triggers the respective serial response.In the ideomotor mechanism,a motor command is exhaustively coded with the intrinsic feedback that it aims to generate.
Greenwald (1970)suggested use of a two-phase experimental method,practice and test,to investigate the ideomotor principle.For the practice phase,a participant is exposed to the contingent triplets of S 1–R 1–E 1repeatedly,and the response (R 1)is condi-tioned to the anticipatory image of distinctive sensory conse-quences (e 1).For the test phase,the combined event of S 1with E 1is presented,and E 1is not a task-relevant stimulus to be per-formed.The response to the target stimulus S 1will be executed faster and more accurately than in the control condition,which is a triplet of three events that has never been experienced before.In the last decade,the experimental paradigm consisting of practice and test phases has become the main setting for investigations of action effects (e.g.,Elsner &Hommel,2001;Kunde,Koch,&Hoffman,2004).
The Theory of Event Coding
The most influential ideomotor theory in recent years is Hom-mel,Mu ¨sseler,Aschersleben,and Prinz’s (2001)theory of event coding (TEC),which is based on a common representational system of perception and action codes.TEC is a theoretical frame-work rather than a fully articulated theory;some of its core concepts,such as event,are loosely defined,although the concepts have been elaborated in later studies (e.g.,Hommel,2007b).Con-sequently,the theory is not easily falsifiable,as the authors men-tioned.They suggested that TEC’s empirical validity could be tested within task-specific models derived from the general theory.TEC has been referred to in more than 300articles and is regarded
1
The original alphabetical denotation that Greenwald used was partially changed to avoid confusion of terms used in this review.Uppercase letters denote overt external events,and lowercase letters denote covert internal state.2
Images refer to “central representations of sensory feedback from responses”(Greenwald,1970,p.
84).
Figure 1.Panels a–d illustrate hypothetical associations in Greenwald’s (1970)ideomotor mechanism.Some of the denotation here was revised,but the basic structure is the same as in Greenwald’s article.The capital letters denote the overt sensory (S for stimulus and E for effect)and motor events (R),and lowercase letters denote internal images of perceivable events.Automatic bonds between events are connected by solid lines,and conditioned bonds are connected by dotted lines.Thus,e n represents internalized image of forthcoming action effect.Repeated experience of stimulus–response and following consistent action effect (Panel a)results in conditioned anticipatory image to a certain stimulus (Panel b),which then becomes anticipatory to the actual effect (Panel c).Panel d demon-strates that the anticipatory images eventually acquire the control over the sequence of the actions.Adapted from “Sensory Feedback Mechanisms in Performance Control:With Special Reference to the Ideo-Motor Mecha-nism,”by A.Greenwald,1970,Psychological Review,77,p.85.Copyright 1970by the American Psychological Association.
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T h i s d o c u m e n t i s c o p y r i g h t e d b y t h e A m e r i c a n P s y c h o l o g i c a l A s s o c i a t i o n o r o n e o f i t s a l l i e d p u b l i s h e r s . T h i s a r t i c l e i s i n t e n d e d s o l e l y f o r t h e p e r s o n a l u s e o f t h e i n d i v i d u a l u s e r a n d i s n o t t o b e d i s s e m i n a t e d b r o a d l y .
as a powerful framework in terms of its heuristic and explanatory power in general.
The following are TEC’s basic assumptions:(a)Perceived and to-be-produced events are represented in a common domain;(b)actions are represented in a similar distributed fashion as percep-tion;(c)the codes referring to the event are part of an abstract and contents-driven distal description rather than a proximal reference of the events;(d)event codes are integrated and activated by two-stage procedures;and (e)event codes are structured with several hierarchical levels.Hommel et al.(2001)noted that TEC incorporates some components from older ideas,especially from the theorists who postulated an integrated relation between per-ception and action planning (e.g.,Gibson,1950).The original ideomotor principle (e.g.,Greenwald,1970;James,1890/1950)also has been reinterpreted in more specific terms.The represen-tational structure of TEC is close to that of a cortical network suggesting that features of the events,such as color,shape,and location,are activated in a distributed fashion (Allport,1987;Singer,1994).How these distributed codes are integrated into one code that refers to one consistent event and how two different codes of stimulus and response can be represented within a com-mon domain are the key issues addressed by TEC.
Event File
How the brain encodes each feature of an object has been studied since the 1960s,and this research has shown the brain system to be highly segregated (e.g.,Livingstone &Hubel,1988).How these distributed features are integrated into one homogenous representation,usually called the binding problem ,has remained a puzzle.Behaviorally,Treisman and Schmidt (1982)and Kahne-man,Treisman,and Gibbs (1992)found that perceiving an event automatically induces binding of the individual codes representing it.Kahneman et al.refined the original feature integration theory by claiming that feature-code bindings are integrated together with more abstract semantic knowledge in an object file .As a knowledge-enriched structure of specific feature combinations,an object file does not just register features of a perceived object but also represents an episodic trace of a particular stimulus perceived in a particular context.
TEC’s core concept of event is a more generalized form of object file.Event file refers to both perception and action descrip-tion.Hommel et al.(2001)defined event as “an easily discrim-inable,well-defined snapshot of the world or a single,discrete movement”(p.864).Every external event,including one’s own action,is coded in an event file.Hommel et al.(2001;Hommel,2003)proposed that planning an action also should be represented in a manner parallel to how visual objects are represented and integrated.Perceiving and action planning are functionally equiv-alent,inasmuch as they are alternative ways of doing the same thing.
Distal Coding of Events
To represent action and perception in a common domain,the codes should refer to distal events in the environment.Hommel (2009)commented that the distal concept is based on terminology from Heider (1926/1959,1930/1959)and Brunswik (1944),who distinguished four different layers of the perceiving world.Ac-
cording to them,the outermost layer is D,which refers to objects,people,and events existing in the real world.These distal things are experienced as beings (D Ј)through transformation of physical attributes of the things (V)such as light or sound energy,which is an incomplete copy of the things,into corresponding neural pat-terns by the sense organs (V Ј).The event code is a modality-free functional description of an object,which represents meaningful interaction of one’s action in the environmental context.Kahne-man et al.(1992)suggested that only a distal and contents-oriented description is functionally and practically usable to describe and control an action consciously.MacKay (1982,1987)also proposed that the end processes of perception and action are highly segre-gated but that the cognitive level of the analysis communicates with the same processing language and in the same way with perception and action.The fine-tuned motor command or reaffer-ent information hardly enters awareness.
Hommel et al.(2001)indicated that TEC’s theoretical scope is limited to the “late”cognitive products of perceptual processing (D Јin the previously discussed terminology)and “early”cognitive antecedents of action.Event codes for action and perception refer to the same distal features in the environment,coded in terms of the perceiver-and-environment relation,including any body-related information.The concept of distal coding is analogous to that of affordance advanced by Gibson (1950).Gibson regarded perception as a process of extracting invariant information about potential contents of action in an optic array;therefore,action does not require transformation of the contents of the perceptual anal-ysis into actionable codes.TEC also suggests that action planning specifies the codes of the intended action features,which are activated when one perceives the stimulus;thus,complex adaptive values like walk-on-ability,grasp-ability,and sit-on-ability are picked up in the course of perceiving.
Hommel et al.(2001)explained how codes are integrated in a common system (see Figure 2).Two feature codes,f 1and f 2
,
Figure 2.Feature coding according to theory of event coding (TEC).In the example,sensory codes coming from two different sensory systems (s 1,s 2,s 3,and s 4,s 5,s 6,respectively)converge onto two abstract feature codes (f 1and f 2)in a common coding system.These feature codes spread their activation to codes belonging to two different motor systems (m 1,m 2,m 3,and m 4,m 5,m 6).Sensory and motor codes refer to proximal information;feature codes in the common coding system refer to distal information.Reprinted from “The Theory of Event Coding (TEC):A Framework for Perception and Action Planning,”by B.Hommel,J.Mu ¨sseler,G.Aschersle-ben,and W.Prinz,2001,Behavioral and Brain Sciences,24,p.862.Copyright 2001by the Cambridge University Press.
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T h i s d o c u m e n t i s c o p y r i g h t e d b y t h e A m e r i c a n P s y c h o l o g i c a l A s s o c i a t i o n o r o n e o f i t s a l l i e d p u b l i s h e r s . T h i s a r t i c l e i s i n t e n d e d s o l e l y f o r t h e p e r s o n a l u s e o f t h e i n d i v i d u a l u s e r a n d i s n o t t o b e d i s s e m i n a t e d b r o a d l y .
denote “left”and “high,”respectively.These codes are made by listening to a high-pitch tone from the left side:f 1receives any perceptual input relating to “left”from the visual system (S 1,S 2)or auditory system (S 4),and f 2processes information relating to “high”from visual system (S 3)and auditory system (S 5and S 6).Each sensory input or motor output refers to proximal information,whereas feature codes are represented in distal information.An action plan can be executed by activation of these feature codes.Activation of f 1may facilitate any “left”action such as saying “left”or moving the eye to the left.Thus,the feature codes control all relevant effectors rather than being limited to a specific mode.Activating features f 1and f 2simultaneously produces a homoge-neous event code;thus,hearing “left”in a high-pitch tone will automatically activate saying “left”in a high-pitch tone.
Remarks on the Ideomotor Mechanism
The core character of ideomotor accounts is that actions are represented in terms of their sensorial effects,which can be clas-sified in different manners.Greenwald (1970)categorized feed-back on the basis of the pathway used to transmit the sensory information.Interoceptive feedback is delivered by propriocep-tion,including kinesthetic or muscular feeling of the movement;in contrast,exteroceptive feedback is delivered by visual,auditory,tactile,and olfactory pathways.Effects can also be categorized by whether the source of information is from the actor’s own body or the outside environment.Resident effects refer to the sensory consequences occurring with body movements,and remote effects are the environmental consequences such as the flight of a ball after one throws it (Hommel et al.,2001).In terms of Greenwald’s categorization,the visual feedback of the arm’s movement trajec-tory is exteroceptive,but in terms of the resident/remote catego-rization,it is resident.When the ball hits the body as a conse-quence of an action,this can be defined as interoceptive and also remote.
The ideomotor accounts take all types of effects into their theoretical consideration,Most ideomotor accounts do not specify which effect type is of concern in their theoretical structure,though mostly exteroceptive and remote effects are manipulated in the experiments.Greenwald (1970)even suggested that his ideomotor analysis could be generalized to extrinsic feedback,which is controlled by an outer mechanism such as reinforcement.Hommel et al.(2001)also conjectured that any kind of action-contingent event (e.g.,turning on a light,producing a tone,pressing a key)could be accommodated by its TEC account.
TEC’s proximal/distal concept is thought to be different from the resident/remote categorization,although Hommel et al.(2001)sometimes used expressions such as proximal effect.The defini-tion is not from the source of the effect or the sensory pathways but from the manner of the coding.As far as perception is concerned,the distal information (D)existing in the world is recovered (D Ј)even with arbitrary encoding (V Ј)of the physical attributes (V).V seems to be inherently ambiguous and noisy,and V Јlacks the richness of the real world,but the correlation between V and V Јis assumed to be high,and the restoration (D Ј)is a veridical repre-sentation of the world (D).
Since only D Јcan be consciously accessed and D Јrefers to the same D for action and perception,this level of information is suggested to be functionally usable to control actions.V layers are
involved in different types of neural activity for processing input and output information and thus are incommensurate.Though the feedback (action effect)is conjectured as a core dynamic force,the ideomotor mechanism can be contrasted with the closed-loop mechanism,in which peripheral information of resident effects is used to update parameters of continuous movements (Adams,1971).Adams hypothesized that feedback from responses leaves a perceptual trace,which is used as a goal to be compared with current performance.If incoming feedback signals a discrepancy from that goal,this difference results in error,and an individual can adjust error by minimizing the difference between performance and paring and correcting error occurs until the movement achieves the final goal state.Hence,adjustment of motor execution emerges from a dynamic interaction between the motor system and the environment.In contrast,the ideomotor principle emphasizes the process of selecting and initiating an action (Kunde et al.,2004),although some authors have suggested that the ideomotor mechanism also serves an evaluative function in that the outcome of the perfor-mance is compared with the intended effect in real time (Band,van Steenbergen,Ridderinkhof,Falkenstein,&Hommel,2009;Nattkem-per &Ziessler,2004).
Reflexive Behavior,Volition,and Consciousness
Another characteristic of ideomotor accounts is immediacy be-tween perception and action,which means that no intermediate steps are required for motor transformation from idea.Thus,al-though ideomotor control is essentially endogenous action starting from a certain intention,it also includes motor activation from a physically given stimulus such as sympathetic,induced actions and stimulus–response compatibility (SRC)effects.Seemingly exoge-nous control is included in ideomotor accounts because (a)the mental and physical events are not dissociable (thus,the physical event is transformed into a mental representation)and (b)when the stimulus itself resembles its anticipatory image,the stimulus acti-vates ideomotor control.
With regard to the ideomotor characteristic of immediacy of action,the role of conscious intent in action control should be identified (Westwood &Goodale,2001).Because of the ill-defined nature of consciousness,the debate about what a conscious process is easily leads to an “agree-to-disagree”argument.Con-sciousness is often defined with a dichotomous description con-trasting it to un-,sub-,or nonconsciousness.Historically,in dual-process theory,controlled versus automatic processing has been stereotyped as denoting conscious versus subconscious processing.Other terms used to represent consciousness include supraliminal ,intentional ,effortful ,serial process ,voluntary ,intelligent ,control-lable ,accessible ,and reportable .In contrast,terms used to repre-sent unconsciousness include subliminal ,unintentional ,effortless ,parallel process ,involuntary ,dumb ,uncontrollable ,inaccessible ,and nonreportable .However,this dichotomous approach has been criticized.For example,Bargh and Morsella (2008)called uncon-sciously controlled behavior,such as highly skilled behavior with-out conscious guidance,intelligent adaptive unconscious behavior ,breaking the boundary of the conscious/unconscious dichotomy.Also,Hommel (2007a)suggested the concept of automatic goal-driven behavior,saying that even an automatic process reflects a current task goal.Nowadays,even a more radical statement is being made:that the acts are essentially unconsciously activated
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T h i s d o c u m e n t i s c o p y r i g h t e d b y t h e A m e r i c a n P s y c h o l o g i c a l A s s o c i a t i o n o r o n e o f i t s a l l i e d p u b l i s h e r s . T h i s a r t i c l e i s i n t e n d e d s o l e l y f o r t h e p e r s o n a l u s e o f t h e i n d i v i d u a l u s e r a n d i s n o t t o b e d i s s e m i n a t e d b r o a d l y .。