Metaphorically feeling: comprehending textural metaphors activates somatosensory cortex

Conceptual metaphor theory suggests that knowledge is structured around metaphorical mappings derived from physical experience. Segregated processing of object properties in sensory cortex allows testing of the hypothesis that metaphor processing recruits activity in domain-specific sensory cortex. Using functional magnetic resonance imaging (fMRI) we show that texture-selective somatosensory cortex in the parietal operculum is activated when processing sentences containing textural metaphors, compared to literal sentences matched for meaning. This finding supports the idea that comprehension of metaphors is perceptually grounded.     

Sources of somatosensory input to the caudal belt areas of auditory cortex

The auditory cortex of nonhuman primates is comprised of a constellation of at least twelve interconnected areas distributed across three major regions on the superior temporal gyrus: core, belt, and parabelt. Individual areas are distinguished on the basis of unique profiles comprising architectonic features, thalamic and cortical connections, and neuron response properties. Recent demonstrations of convergent auditory-somatosensory interactions in the caudomedial (CM) and caudolateral (CL) belt areas prompted us to pursue anatomical studies to identify the source(s) of somatic input to auditory cortex. Corticocortical and thalamocortical connections were revealed by injecting neuroanatomical tracers into CM, CL, and adjoining fields of marmoset (Callithrix jacchus jacchus) and macaque (Macaca mulatta) monkeys. In addition to auditory cortex, the cortical connections of CM and CL included somatosensory (retroinsular, Ri; granular insula, Ig) and multisensory areas (temporal parietal occipital, temporal parietal temporal). Thalamic inputs included the medial geniculate complex and several multisensory nuclei (suprageniculate, posterior, limitans, medial pulvinar), but not the ventroposterior complex. Injections of the core (A1, R) and rostromedial areas of auditory cortex revealed sparse multisensory connections. The results suggest that areas Ri and Ig are the principle sources of somatosensory input to the caudal belt, while multisensory regions of cortex and thalamus may also contribute. The present data add to growing evidence of multisensory convergence in cortical areas previously considered to be 'unimodal', and also indicate that auditory cortical areas differ in this respect.     

Role of the primary somatosensory cortex in motor learning: An rTMS study

Somatosensation is thought to play an important role in skilled motor learning. The present study investigated how healthy adults learn a continuous implicit motor task when somatosensation is altered by 1 Hz repetitive transcranial magnetic stimulation (rTMS) delivered over the primary somatosensory cortex (S1). Twenty-seven right-handed participants enrolled in a two-part experiment. In Experiment 1, we verified that 20 min of 1 Hz rTMS over S1 disrupted cutaneous somatosensation (indexed by two-point discrimination) in the wrist/hand; the impact of 1 Hz rTMS on wrist proprioception (tested by limb-position matching) was variable. Sham rTMS had no effect on either measure. We exploited these effects in Experiment 2 by pairing either 1 Hz or sham rTMS with practice of a continuous tracking task over two separate sessions on different days. Implicit motor learning was indexed on a third, separate retention test day when no rTMS was delivered. Across practice in Experiment 2, both the 1 Hz and sham rTMS groups showed improved tracking performance; however, 1 Hz rTMS was associated with less accurate tracking and smaller improvements in performance. Importantly, at the no rTMS retention test the effects of altering sensation with stimulation over S1 were still evident in the persistently less accurate tracking behavior of the 1 Hz rTMS group. The current study shows that disruption of somatosensation during task practice impairs the magnitude of change associated with motor learning, perhaps through the development of an inaccurate internal model.     

A somatosensory latency between the thalamus and cortex also correlates with level of intelligence

As part of a study on speed of information processing and intelligence, 205 young adult postsecondary students were tested for somatosensory evoked potential (SEP) latencies and intelligence. Following stimulation at the wrist, latencies of three SEPs were determined: N13, generated in the cervical spinal cord/medulla region; N19, generated in the thalamus; P22, generated in the arm region of the somatosensory (parietal) cortex. These latencies and two latency differences, N19 - N13 and P22 - N19, were tested for correlation with a nonverbal measure of intelligence; only P22 - N19 significantly correlated (r = −.217; P = .013, two-tailed). Comparing this latency difference in students in the first IQ quartile (mean IQ = 103.4) with that of students in the fourth quartile (M = 131.2) showed mean differences of 4.13 ms versus 3.21 ms, respectively (p = .0034, two-tailed).P22 - N19 measures time for signal transmission from the thalamus to the sensory cortex. These results agree with considerably more extensive data on visually evoked potentials showing a negative correlation between IQ and the latency for a visual stimulus of the retina to produce a signal at the visual cortex (most of this latency is between the thalamus and the cortex; Reed & Jensen, 1992). The findings here agree with the visual results and strongly suggest that the IQ-latency correlation occurs because the latency indexes cortical nerve conduction velocity, an important component of information processing speed.     

Understanding the dorsal and ventral systems of the human cerebral cortex: beyond dichotomies

Traditionally, characterizations of the macrolevel functional organization of the human cerebral cortex have focused on the left and right cerebral hemispheres. However, the idea of left brain versus right brain functions has been shown to be an oversimplification. We argue here that a top-bottom divide, rather than a left-right divide, is a more fruitful way to organize human cortical brain functions. However, current characterizations of the functions of the dorsal (top) and ventral (bottom) systems have rested on dichotomies, namely where versus what and how versus what. We propose that characterizing information-processing systems leads to a better macrolevel organization of cortical function; specifically, we hypothesize that the dorsal system is driven by expectations and processes sequences, relations, and movement, whereas the ventral system categorizes stimuli in parallel, focuses on individual events, and processes object properties (such as shape in vision and pitch in audition). To test this hypothesis, we reviewed over 100 relevant studies in the human neuroimaging and neuropsychological literatures and coded them relative to 11 variables, some of which characterized our hypothesis and some of which characterized the previous dichotomies. The results of forward stepwise logistic regressions supported our characterization of the 2 systems and showed that this model predicted the empirical findings better than either the traditional dichotomies or a left-right difference.     

Cortical spreading depression and involvement of the motor cortex,auditory cortex,and cerebellum in eyeblink classical conditioning of the rabbit

The interrelationships of cerebellar and cerebral neural circuits in the eyeblink paradigm were explored with the controlled application of cortical spreading depression (CSD) and lidocaine in the New Zealand albino rabbit. The initial research focus was directed toward the involvement of the motor cortex in the conditioned eyeblink response. However, CSD timing and triangulation results indicate that other areas in the cerebral cortex, particularly the auditory cortex (acoustic conditioned stimulus), appear to be critical for the CSD effect on the eyeblink response. In summary: (1) CSD can be elicited, monitored, and timed and its side effects controlled in 97% of awake rabbits in the right and/or left cerebral hemisphere(s) during eyeblink conditioning. (2) The motor cortex appears to play little or no part in classical conditioning of the eyeblink in the rabbit in the delay paradigm. (3) Inactivating the auditory cortex with CSD or lidocaine temporarily impairs the conditioned response during the first 5 to 15 days of training, but has little effect past that point.     

Direction- and velocity-specific responses from beyond the classical receptive field in the middle temporal visual area (MT)

The true receptive field of more than 90% of neurons in the middle temporal visual area (MT) extends well beyond the classical receptive field (crf), as mapped with conventional bar or spot stimuli, and includes a surrounding region that is 50 to 100 times the area of the crf. These extensive surrounds are demonstrated by simultaneously stimulating the crf and the surround with moving stimuli. The surrounds commonly have directional and velocity-selective influences that are antagonistic to the response from the crf. The crfs of MT neurons are organized in a topographic representation of the visual field. Thus MT neurons are embedded in an orderly visuotopic array, but are capable of integrating local stimulus conditions within a global context. The extensive surrounds of MT neurons may be involved in figure-ground discrimination, preattentive vision, perceptual constancies, and depth perception through motion cues.     

The prefrontal-thalamic axis and classical conditioning.

Using the New Zealand albino rabbit as an animal model, it has been determined that the medial prefrontal cortex is intimately involved in, and may be necessary for, acquisition of classically conditioned bradycardia. The interconnected nuclei of the medial thalamus, most notably the mediodorsal nucleus, conversely appear to be associated with the development of the tachycardia that accompanies classical conditioning of the eyeblink and nictitating membrane response. Neuroanatomical, electrophysiological, brain stimulation, and lesion data are reviewed, which support the conclusion that the prefrontal-thalamic axis is intimately involved in acquisition of classically conditioned visceral changes.     

IJPR: beyond the limit and limiting the beyond

It is now almost 20 years since Janicaud’s critique of the ‘theological turn in French phenomenology’ (Janicaud 1991, 2000), with its emphasis on phenomenology and theology as two and never one. Yet since that time there been an explosion of phenomenologies which are, if not overtly, implicitly religious and phenomenology. Thus, we have phenomenologies of prayer, or love, or hope, and the possibilities of further phenomenologies. The challenge of these emerging phenomenologies is that there seems to be no noematic correlate to a noesis in intentionality. To the fore in the reconsideration of this phenomenological challenge is Jean-Luc Marion (although there are others such as Levinas, Jean-Louis Chrétien, and Michel Henry): all aspects of lived experience appear now to belong to the proper scope of phenomenology. Marion considers the relation in Husserl between intentions and intuitions which fulfil these intentions, and suggests a reversal. In Marion, although intentionality is not rejected, the phenomenological flow which the reduction brings to light is from the object as such as it gives itself in intuition, and then from intuition to intention. For Marion, phenomena are saturated—they give too much. Religion becomes a test-case for all phenomenology. This bearing, drawing mainly on The Visible and the Revealed, offers some of the key things in Marion’s phenomenology.     

Team effectiveness: beyond skills and cognitive ability.

On the basis of job analysis results, the validity of using measures of general cognitive ability, job-specific skills, and personality traits jointly at both the individual level and the group level to predict the performance of 79 four-person, human resource work teams was evaluated. Team member trait and job skill scores were aggregated with a conjunctive model of task performance. At the individual level of analysis, measures of personality (i.e., Agreeableness and Conscientiousness) predicted peer ratings of team member performance beyond measures of job-specific skills and general cognitive ability. Similarly, at the group level of analysis, both Agreeableness and Conscientiousness predicted supervisor ratings of work team performance, objective measures of work team accuracy, and work completed. At both the individual and group levels, the trait of Agreeableness predicted Interpersonal Skills.     

Human classical conditioning. The status of the CS

Recent reports of failure to obtain blocking in human galvanic skin response (GSR) conditioning, together with our own equivocal results with eyelid conditioning, have motivated us to re-examine the status of the conditioned stimulus (CS) in human conditioning studies. The issues raised by compound stimuli, by contextual cues and occasion setting stimuli, and by cross-modal transfer are considered in the light of data from our laboratories. These data include observations on the interchangeability of stimulus modalities during acquisition, the use of varying information loads embedded in occasion setting displays, the comparison of alternative blocking designs and the analysis of response topography in relation to stimulus variability. They suggested that an adequate account of the CS in human conditioning studies must recognize that it is dynamically processed and reprocessed both during and after acquisition.     

Deflationism beyond arithmetic

The conservativeness argument poses a dilemma to deflationism about truth, according to which a deflationist theory of truth must be conservative but no adequate theory of truth is conservative. The debate on the conservativeness argument has so far been framed in a specific formal setting, where theories of truth are formulated over arithmetical base theories. I will argue that the appropriate formal setting for evaluating the conservativeness argument is provided not by theories of truth over arithmetic but by those over subject matters ‘richer’ than arithmetic, such as set theory. The move to this new formal setting provides deflationists with better defence and brings a broader perspective to the debate.