Motor fluency shapes abstract concepts

People with different types of bodies tend to think differently in predictable ways, even about abstract ideas that seem far removed from bodily experience. Right- and left-handers implicitly associate positive ideas like goodness and honesty more strongly with their dominant side of space, the side on which they can interact with their environment more fluently, and negative ideas with their non-dominant side. This suggests a role for motor experience in shaping abstract thoughts. Yet, previous evidence is also consistent with an experience-independent account. Here we show that right-handers' tendency to associate 'good' with right and 'bad' with left can be reversed due to both long- and short-term changes in motor fluency. Among stroke patients who were right-handed prior to unilateral cerebrovascular accident (CVA), those with left-hemiparesis (following right CVA) associated good with right, but those with right-hemiparesis (following left CVA) associated good with left, like natural left-handers. A similar pattern was found in healthy right-handers whose right or left hand was temporarily handicapped in a laboratory training task. Motor experience influences judgments of good and bad, overriding any predispositions due to natural handedness. Even highly abstract ideas depend, in part, on how people interact with the physical world

Neural Basis of Motivation Lateralizes with Motor Control

According to decades of research on affective motivation in the human brain, approach motivational states are subserved by the left hemisphere and avoidance states by the right hemisphere. Here we show that hemispheric specialization for motivation reverses with handedness. This covariation provides initial support for the Sword and Shield Hypothesis, according to which hemispheric laterality of affective motivation is causally linked to motor control for the dominant and non-dominant hands

Body-specific representations of action word meanings in right and left handers

If understanding action words involves mentally simulating our own actions, then the neurocognitive representation of word meanings must differ for people with different kinds of bodies, who perform actions in systematically different ways. In a test of the _Body-Specificity Hypothesis_, right- and left-handers were compared on two motor-meaning congruity tasks. Double dissociations in both action execution and recognition memory results showed that right and left handers form body-specific representations of words for manual actions

Perceptual foundations of abstract thought

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Brain and Cognitive Sciences, 2005.Includes bibliographical references (p. 75-78).How do people think about things they can never see or touch? The ability to invent and reason about domains such as time, ideas, or mathematics is uniquely human, and is arguably the hallmark of human sophistication. Yet, how people mentally represent these abstract domains has remained one of the great mysteries of the mind. This dissertation explores a potential solution: perhaps the mind recruits old structures for new uses. Perhaps sensory and motor representations that result from physical interactions with the world (e.g., representations of physical space) are recycled to support our thinking about abstract phenomena. This hypothesis is motivated, in part, by patterns observed in language: in order to talk about abstract things, speakers often recruit metaphors from more concrete or perceptually rich domains. For example, English speakers often talk about time using spatial language (e.g., a long vacation; a short meeting). Cognitive linguists have argued such expressions reveal that people conceptualize abstract domains like time metaphorically, in terms of space. Although linguistic evidence for this Conceptual Metaphor Theory is abundant, the necessary nonlinguistic evidence has been elusive.(cont.) In two series of experiments, I investigated whether mental representations that result from physical experience underlie people's more abstract mental representations, using the domains of space and :!I.:e as a testbed. New experimental tools were developed in order to evaluate Conceptual Metaphor Theory as an account of the evolution and structure of abstract concepts, and to explore relations between language and nonlinguistic thought. Hypotheses about the way people represent space and time were based on patterns in metaphorical language, but were tested using simple psychophysical tasks with nonlinguistic stimuli and responses. Results of the first set of experiments showed that English speakers incorporate irrelevant spatial information into their estimates of time (but not vice versa), suggesting that people not only talk about time using spatial language, but also think about time using spatial representations. The second set of experiments showed that (a) speakers of different languages rely on different spatial metaphors for duration, (b) the dominant metaphor in participants' first languages strongly predicts their performance on nonlinguistic time estimation tasks, and (c) training participants to use new spatiotemporal metaphors in language changes the way they estimate time.(cont.) Together, these results demonstrate that the metaphorical language people use to describe abstract phenomena provides a window on their underlying mental representations, and also shapes those representations. The structure of abstract domains such as time appears to depend, in part, on both linguistic experience and on physical experience in perception and motor action.by Daniel J. Casasanto.Ph.D

Stepping out of the Chinese Room: Word meaning with and without consciousness

What is the role of consciousness in language processing? Unconscious priming experiments show that words can prime other words with related meanings (cat \u2013 dog), and these priming effects are assumed to reflect the activation of conceptual knowledge in semantic memory. Alternatively, however, unconscious priming effects could reflect predictive relationships between the words\u2019 forms, since words that are semantically related are also statistically related in language use. Therefore, unconscious \u201csemantic\u201d priming effects could be due to relationships between words\u2019 forms mimicking conceptual relationships, as in Searle\u2019s Chinese Room thought experiment. To distinguish wordform-based and semantics-based accounts of priming we conducted an experiment in which temporal words (e.g., earlier, later) were preceded by spatial words that were processed either consciously or unconsciously. Time is typically conceptualized as a spatial continuum extending along either the sagittal (front-back) or the lateral (left-right) axis, but only the sagittal space-time mapping is encoded in language (e.g. the future is ahead, not to the right). Results showed that temporal words were primed both by sagittal words (back, front) and lateral words (left, right) when primes were perceived consciously, as predicted by both wordformbased and semantics-based accounts. Yet, only sagittal words produced an unconscious priming effect, as predicted by the wordform-based account. Unconscious word processing appears to be limited to relationships between words\u2019 forms, and consciousness may be needed to activate words\u2019 meanings

Body-Specific Motor Imagery of Hand Actions: Neural Evidence from Right- and Left-Handers

If motor imagery uses neural structures involved in action execution, then the neural correlates of imagining an action should differ between individuals who tend to execute the action differently. Here we report fMRI data showing that motor imagery is influenced by the way people habitually perform motor actions with their particular bodies; that is, motor imagery is ‘body-specific’ (Casasanto, 2009). During mental imagery for complex hand actions, activation of cortical areas involved in motor planning and execution was left-lateralized in right-handers but right-lateralized in left-handers. We conclude that motor imagery involves the generation of an action plan that is grounded in the participant's motor habits, not just an abstract representation at the level of the action's goal. People with different patterns of motor experience form correspondingly different neurocognitive representations of imagined actions

The QWERTY Effect: How typing shapes the meanings of words.

The QWERTY keyboard mediates communication for millions of language users. Here, we investigated whether differences in the way words are typed correspond to differences in their meanings. Some words are spelled with more letters on the right side of the keyboard and others with more letters on the left. In three experiments, we tested whether asymmetries in the way people interact with keys on the right and left of the keyboard influence their evaluations of the emotional valence of the words. We found the predicted relationship between emotional valence and QWERTY key position across three languages (English, Spanish, and Dutch). Words with more right-side letters were rated as more positive in valence, on average, than words with more left-side letters: the QWERTY effect. This effect was strongest in new words coined after QWERTY was invented and was also found in pseudowords. Although these data are correlational, the discovery of a similar pattern across languages, which was strongest in neologisms, suggests that the QWERTY keyboard is shaping the meanings of words as people filter language through their fingers. Widespread typing introduces a new mechanism by which semantic changes in language can arise

Functional MRI and the Wada test provide complementary information for predicting post-operative seizure control

AbstractPrediction of post-surgical seizure relief and potential cognitive deficits secondary to anterior temporal lobectomy (ATL) are important to pre-surgical planning. Although the intracarotid amobarbital test (IAT) is predictive of post-ATL seizure outcome, development of non-invasive and more precise means for determining post-ATL seizure relief are needed. We previously reported on a technique utilizing functional MRI (fMRI) to evaluate the relative functional adequacy of mesial temporal lobe structures in preparation for ATL . In the present study, we report follow-up outcome data on eight temporal lobe epilepsy (TLE) patients 1-year post-ATL who were evaluated pre-surgically using IAT and fMRI. Functional memory lateralization using fMRI predicted post-ATL seizure outcome as effectively as the IAT. In general, asymmetry of functional mTL activation favouring the non-epileptic hemisphere was associated with seizure-free status at 1-year follow-up. Moreover, when combined, fMRI and IAT provided complementary data that resulted in improved prediction of post-operative seizure control compared with either procedure alone

Good and Bad in the Hands of Politicians: Spontaneous Gestures during Positive and Negative Speech

According to the body-specificity hypothesis, people with different bodily characteristics should form correspondingly different mental representations, even in highly abstract conceptual domains. In a previous test of this proposal, right- and left-handers were found to associate positive ideas like intelligence, attractiveness, and honesty with their dominant side and negative ideas with their non-dominant side. The goal of the present study was to determine whether ‘body-specific’ associations of space and valence can be observed beyond the laboratory in spontaneous behavior, and whether these implicit associations have visible consequences

Motivation and Motor Control: Hemispheric Specialization for Approach Motivation Reverses with Handedness

(SSH), according to which the hemispheric laterality of affective motivation depends on the laterality of motor control for the dominant hand (i.e., the “sword hand," used preferentially to perform approach actions) and the nondominant hand (i.e., the “shield hand," used preferentially to perform avoidance actions).To determine whether the laterality of approach motivation varies with handedness, we measured alpha-band power (an inverse index of neural activity) in right- and left-handers during resting-state electroencephalography and analyzed hemispheric alpha-power asymmetries as a function of the participants' trait approach motivational tendencies. Stronger approach motivation was associated with more left-hemisphere activity in right-handers, but with more right-hemisphere activity in left-handers.The hemispheric correlates of approach motivation reversed between right- and left-handers, consistent with the way they typically use their dominant and nondominant hands to perform approach and avoidance actions. In both right- and left-handers, approach motivation was lateralized to the same hemisphere that controls the dominant hand. This covariation between neural systems for action and emotion provides initial support for the SSH