An fMRI investigation on image generation in different sensory modalities: The influence of vividness

In the present fMRI study the issue of the specific cortices activation during imagery generation in different sensory modalities is addressed. In particular, we tested whether the vividness variability of imagery was reflected in the BOLD signal within specific sensory cortices. Subjects were asked to generate a mental image for each auditory presented sentence. Each imagery modality was contrasted with an abstract sentence condition. In addition, subjects were asked to fill the Italian version of the Questionnaire Upon Mental Imagery (QMI) prior to each neuroimaging session. In general, greater involvement of sensory specific cortices in high-vivid versus low-vivid subjects was found for visual (occipital), gustatory (anterior insula), kinaesthetic (pre-motor), and tactile and for somatic (post-central parietal) imagery modalities. These results support the hypothesis that vividness is related to image format: high-vivid subjects would create more analogical representations relying on the same specific neural substrates active during perception with respect to low-vivid subjects. Results are also discussed according to the simulation perspective.     

Articulatory/phonetic sequencing at the level of the anterior perisylvian cortex: a functional magnetic resonance imaging (fMRI) study

Damage to the anterior peri-intrasylvian cortex of the dominant hemisphere may give rise to a fairly consistent syndrome of articulatory deficits in the absence of relevant paresis of orofacial or laryngeal muscles (apraxia of speech, aphemia, or phonetic disintegration). The available clinical data are ambiguous with respect to the relevant lesion site, indicating either dysfunction of the premotor aspect of the lower precentral gyrus or the anterior insula in the depth of the Sylvian fissure. In order to further specify the functional anatomic substratum of this syndrome, functional magnetic resonance imaging (fMRI) was performed during reiteration of syllables differing in their demands on articulatory/phonetic sequencing (CV versus CCCV versus CVCVCV). Horizontal tongue movements and a polysyllabic lexical item served as control conditions. Repetition of the CV and CCCV monosyllables elicited a rather bilateral symmetric hemodynamic response at the level of the anterior and posterior bank of the central sulcus (primary sensorimotor cortex), whereas a more limited area of neural activity arose within this domain during production of lexical and nonlexical polysyllables, significantly or exclusively lateralized toward the left hemisphere. There is neurophysiological evidence that primary sensorimotor cortex mediates the "fractionation" of movements. Assuming that the polysyllables considered are organized as coarticulated higher-order units, the observed restricted and lateralized cortical activation pattern, most presumably, reflects a mode of "nonindividualized" motor control posing fewer demands on "movement fractionation." These findings may explain the clinical observation of disproportionately worse repetition of trisyllabic items as compared to monosyllables in apraxia of speech. The various test materials failed to elicit significant activation of the anterior insula. If at all, only horizontal tongue movements yielded a hemodynamic reaction extending beyond the sensorimotor cortex to premotor areas. Since limbic projections target the inferior dorsolateral frontal lobe, the enlarged region of activation during horizontal tongue movements might reflect increased attentional requirements of this task.     

The contribution of the insula to motor aspects of speech production: a review and a hypothesis

Based on clinical and functional imaging data, the left anterior insula has been assumed to support prearticulatory functions of speech motor control such as the "programming" of vocal tract gestures. In order to further elucidate this model, a recent functional magnetic resonance imaging (fMRI) study of our group (Riecker, Ackermann, Wildgruber, Dogil, & Grodd, 200) investigated both overt (aloud) and covert (silent) production of highly overlearned word strings ("automatic speech"), based on the suggestion that "inner speech" might provide a "window" into preparatory motor activities (Jeannerod, 1994). As a control condition, subjects were asked to reproduce a nonlyrical tune. In contrast to hemodynamic responses within motor cortex and cerebellum, activation of the intrasylvian cortex turned out to be bound to overt task performance. Rather than prearticulatory processes, these findings suggest the left insula to contribute to the actual coordination of the up to 100 muscles engaged in articulation and phonation. Conceivably, the association of speech production with intrasylvian cortex might have evolved within the framework of phylogenetically older connections between the insula and limbic structures, on the one hand, and nonspeech functions of the upper midline musculature such as swallowing, on the other. Whereas (overt) speech tasks predominantly elicit activation within left anterior insula, reproduction of a nonlyrical tune yielded an opposite response pattern. Conceivably, the opposite distributional pattern of speaking and singing at the level of intrasylvian cortex reflects operation of the two hemispheres across different time domains ("double filtering by frequency theory": left hemisphere=segmental information, right hemisphere=intonation contours of verbal utterances and musical melodies; ). In line with this suggestion, a further study of our group (Ackermann et al., 2001) provided first evidence that differential hemispheric filtering might be bound to insular cortex.     

Gustatory plasticity in C. elegans involves integration of negative cues and NaCl taste mediated by serotonin, dopamine, and glutamate

While na?ve Caenorhabditis elegans individuals are attracted to 0.1-200 mM NaCl, they become strongly repelled by these NaCl concentrations after prolonged exposure to 100 mM NaCl. We call this behavior gustatory plasticity. Here, we show that C. elegans displays avoidance of low NaCl concentrations only when pre-exposure to NaCl is combined with a negative stimulus, e.g., a repellent, or in the absence of food. By testing serotonin and/or dopamine signaling mutants and rescue by exogenously supplying these neurotransmitters, we found that serotonin and dopamine play a role during the plasticity response, while serotonin is also required during development. In addition, we also show that glutamate plays an important role in the response to NaCl, both in chemoattraction to NaCl and in gustatory plasticity. Thus, C. elegans can associate NaCl with negative stimuli using dopaminergic, serotonergic, and glutamatergic neurotransmission. Finally, we show that prolonged starvation enhances gustatory plasticity and can induce avoidance of NaCl in most gustatory plasticity mutants tested. Only mutation of the glutamate-gated Cl(-) channel gene avr-15 affected starvation-enhanced gustatory plasticity. These results suggest that starvation induces avoidance of NaCl largely independent of the normal gustatory plasticity mechanism.     

Contributions of the Insula to Cognition and Emotion

Historically, the insula was considered primary gustatory cortex. Now it is known to play a more comprehensive role in the processing of sensory information, including acting as primary cortex for interoceptive information, including autonomic nervous system mediated changes. As such, it is critical for emotional feeling in accord with the James-Lange theory, a role previously ascribed to the limbic system. Neuroimaged abnormal grey matter volumes or activity levels in the insula have been associated with schizophrenia, eating disorders, anxiety and mood disorders, conduct disorder, autism, addiction, and chronic pain. The significance of these abnormal activity patterns remains theoretical. Neuropsychological studies have linked dominant insula injury with various symptoms of aphasia, but its exact role in language processing remains uncertain as most cases involve lesions that extend into perisylvian language zones. Functional neuroimaging studies have found insula hyper-activations, typically in conjunction with anterior cingulate cortex, for all manner of experimental tasks including those involving perception, intentional action, and consciousness. Such neuroimaged activity is unlikely to be task-specific, but rather reflective of generic changes in autonomic activity in response to salience, homeostatic incongruence, or cognitive challenge.     

MOOD AND WELL-BEING IN CONSECUTIVE MENSTRUAL CYCLES Methodological and Theoretical Implications

The level of consistency of cyclical change in well-being between consecutive menstrual cycles has important methodological, clinical, and theoretical implications. In this study, 109 women completed daily diaries of mood and physical well-being for two consecutive menstrual cycles. Scores in equivalent cycle phases were highly correlated, but the degree and direction of change from the pre-post menstrual phase were less consistent between cycles. Physical experiences proved more consistent across cycles than did emotional ones. Only 5.4% (nonsteroidal contraceptive users) and 7.8% (oral contraceptive users) of Cycle 2 emotional score variance could be accounted for by Cycle 1 scores compared to 15% and 22%, respectively, for physical scores. The data indicate that premenstrual experiences vary between menstrual cycles, and suggest that they cannot be adequately explained on the basis of simple biological determinism. Methodological and theoretical implications of the results are discussed.     

Health and Sickness: The Meaning of Menstruation and Premenstrual Syndrome in Women's Lives

The experience of menstruation was examined through an analysis of women's narratives in order to understand perceptions of menstrual cycle changes. Research within a medical anthropology perspective was conducted with 43 women who volunteered for a study on the knowledge and understanding of menstruation and premenstrual syndrome (PMS) in Winnipeg, Manitoba, Canada, from 1997 to 1999. Although most women accepted the PMS label and placed their cyclic changes within the realm of sickness, a small group of women were identified who conceptualized their cyclic changes in an extremely positive way thus reframing their experiences. More positive perceptions of menstrual changes may have a significant impact on the reevaluation of menstrual cycle fluctuations as sickness without devaluing the experiences of those women with severe changes.     

Manipulating basic taste perception to explore how product information affects experience

We introduce a novel physiologically-based methodology to consumer research—using the glycoprotein miraculin to manipulate the ability to sense and perceive specific taste elements in gustatory experiences. We apply this approach to exploring how information extrinsic (e.g., product reviews) to a product's inherent sensory facets influences reported consumption experiences and experienced utility. Results from two experiments suggest that extrinsic information distorts the basic sensory and perceptual character of consumption experiences, rather than simply biasing self-reports of the experiences or serving as an independent input to overall taste and utility evaluations. Such evaluations are distorted in the direction of extrinsic product information only when the ability to actually perceive the experience as being consistent with the extrinsic signal is not disrupted by miraculin. Conversely, disruption by miraculin of the ability to perceive an experience as being consistent with an extrinsic signal ablates or reverses such effects. Implications, applications to brands and branding, and other possible research directions for the miraculin taste-manipulation methodology are also discussed.     

Information-seeking and maternal self-definition during the transition to motherhood

The self-definitional processes accompanying the transition to motherhood were examined in this study. A cross-sectional sample of more than 600 women who were planning to get pregnant within 2 years, pregnant, or in the postpartum stage completed extensive questionnaires pertaining to their experiences of pregnancy and motherhood. On the basis of the assumption of the "self-socialization" perspective that individuals actively construct their identities in response to life transitions, our analyses focused on the role of information-seeking in the developing self-definitions of women becoming mothers. As predicted, (a) women actively sought information in anticipation of a first birth, (b) they used this information to construct identities incorporating motherhood, and (c) after the birth the determinants of their self-definitions shifted from indirect sources of information to direct experiences with child care. Hence, consistent with the self-socialization perspective, information-seeking did play an important role in the women's developing self-conceptions during this life transition. Mechanisms by which information gathered may alter self-conception are discussed.     

Human trace fear conditioning: right-lateralized cortical activity supports trace-interval processes

Pavlovian conditioning requires the convergence and simultaneous activation of neural circuitry that supports conditioned stimulus (CS) and unconditioned stimulus (US) processes. However, in trace conditioning, the CS and US are separated by a period of time called the trace interval, and thus do not overlap. Therefore, determining brain regions that support associative learning by maintaining a CS representation during the trace interval is an important issue for conditioning research. Prior functional magnetic resonance imaging (fMRI) research has identified brain regions that support trace-conditioning processes. However, relatively little is known about whether this activity is specific to the trace CS, the trace interval, or both periods of time. The present study was designed to disentangle the hemodynamic response produced by the trace CS from that associated with the trace interval, in order to identify learning-related activation during these distinct components of a trace-conditioning trial. Trace-conditioned activity was observed within dorsomedial prefrontal cortex (PFC), dorsolateral PFC, insula, inferior parietal lobule (IPL), and posterior cingulate (PCC). Each of these regions showed learning-related activity during the trace CS, while trace-interval activity was only observed within a subset of these areas (i.e., dorsomedial PFC, PCC, right dorsolateral PFC, right IPL, right superior/middle temporal gyrus, and bilateral insula). Trace-interval activity was greater in right than in left dorsolateral PFC, IPL, and superior/middle temporal gyrus. These findings indicate that components of the prefrontal, cingulate, insular, and parietal cortices support trace-interval processes, as well as suggesting that a right-lateralized fronto-parietal circuit may play a unique role in trace conditioning.     

The influence of syllable onset complexity and syllable frequency on speech motor control

Functional imaging studies have delineated a "minimal network for overt speech production", encompassing mesiofrontal structures (supplementary motor area, anterior cingulate gyrus), bilateral pre- and postcentral convolutions, extending rostrally into posterior parts of the inferior frontal gyrus (IFG) of the language-dominant hemisphere, left anterior insula as well as bilateral components of the basal ganglia, the cerebellum, and the thalamus. In order to further elucidate the specific contribution of these cerebral regions to speech motor planning, subjects were asked to read aloud visually presented bisyllabic pseudowords during functional magnetic resonance imaging (fMRI). The test stimuli systematically varied in onset complexity (CCV versus CV) and frequency of occurrence (high-frequency, HF versus low-frequency, LF) of the initial syllable. A cognitive subtraction approach revealed a significant main effect of syllable onset complexity (CCV versus CV) at the level of left posterior IFG, left anterior insula, and both cerebellar hemispheres. Conceivably, these areas closely cooperate in the sequencing of subsyllabic aspects of the sound structure of verbal utterances. A significant main effect of syllable frequency (LF versus HF), by contrast, did not emerge. However, calculation of the time series of hemodynamic activation within the various cerebral structures engaged in speech motor control revealed this factor to enhance functional connectivity between Broca's area and ipsilateral anterior insula.     

The sensed presence within experimental settings: implications for the male and female concept of self

The sense of "a presence" or of a sentient being during partial sensory deprivation and exposure to very weak, complex magnetic fields across the cerebral hemispheres may be a normal neurocognitive experience that is associated with the brief intrusion of the right hemispheric homologue of the left hemispheric (and strongly linguistic) sense of self into awareness. Within an optimal experimental setting, women reported more frequent experiences of a sensed presence than did men, and men were more likely than women to consider these experiences as "intrusions" from extrapersonal or ego-alien sources. Both effects were predicted by the vectorial hemisphericity hypothesis and the known neurocognitive differences between right-handed men and right-handed women. Sociobiological implications for gender differences in the probability of intercalation between distinctive processes within the left and right temporoparietal lobes are discussed.     

Temporal lobe signs: electroencephalographic validity and enhanced scores in special populations

Internal and external validity tests were completed for an inventory that has been used to infer signs of temporal lobe lability. Strong, positive correlations were reported for a normal (reference) population between the numbers of responses that referred to paranormal experiences (including feelings of a "presence") and separately to religious beliefs and the numbers of spikes per minute within electroencephalographic recordings from the temporal lobe. Numbers of spikes were also correlated with the subjects' scores on the hysteria, schizophrenia, and psychasthenia scales from the MMPI. These clusters of items were not correlated with electrical activity from the occipital lobe (the comparison region). Numbers of responses to control clusters of mundane experiences were not correlated with the temporal lobe measures. A group of student poets scored higher on different subclusters of temporal lobe signs and on the schizophrenia and mania scales of the MMPI than the reference group. For both groups, there were positive correlations between the amount of alpha activity in the temporal lobe only and answers to items such as "hearing inner voices" and "feeling as if things were not real." These results demonstrate that quantitative measures of electrical changes in the temporal lobe are correlated with (or with the report of) specific experiences that are prevalent during surgical or epileptic stimulation of this brain region.     

Person perception across the menstrual cycle: hormonal influences on social-cognitive functioning

Women's reactions to men shift during the menstrual cycle. For example, during the phase of high conception risk, women prefer men with masculinized facial features. A favored explanation for this effect is that women display an enhanced sensitivity to stimuli that have significant reproductive relevance during the phase of the menstrual cycle in which conception risk is high. Consistent with this viewpoint, the present research demonstrated that women's cycle–dependent attentiveness to "maleness" also extends to basic aspects of the person–perception process. Specifically, during the phase of high conception risk, women displayed an enhanced ability both to categorize men and to access associated category–related (i.e., stereotypic) material from semantic memory. The implications of these findings for contemporary treatments of person perception are considered.     

Bidirectional lexical-gustatory synesthesia

In developmental lexical–gustatory synesthesia, specific words (inducers) can trigger taste perceptions (concurrents) and these synesthetic associations are generally stable. We describe a case of multilingual lexical–gustatory synesthesia for whom some synesthesias were bidirectional as some tastes also triggered auditory word associations. Evoked concurrents could be gustatory but also tactile sensations. In addition to words and pseudowords, many voices were effective inducers, suggesting increased connections between cortical taste areas and both voice-selective and language-selective areas. Lasting changes in some evoked tastes occurred during childhood suggesting that some plasticity can be present after the initial learning of associations. Inducers were often linked to taste concurrents phonologically or semantically, but also through identifiable childhood episodes (persons or events). Several inducers were phonologically linked to episodic inducers suggesting a process of secondary acquisition for many inducers. Implications of these observations are discussed.     

Correlation between menstrual cycle and cognitive performance in a chimpanzee (Pan troglodytes)

Extensive research on human subjects has tried to investigate whether there is a correlation between cognitive performance and the menstrual cycle. Less is known about the relationship between the menstrual cycle and task performance in other cognitive animals. We test whether the secretion of a sex hormone [luteinizing hormone(LH)] influences the performance of cognitive tasks by a female chimpanzee (Pan troglodytes) who is part of a long-term cognition research program. We focus on two cognitive tasks: an "easy task," which consists of simple numerical ordering, and a "difficult task," which combines numerical ordering with memorizing the numerals' spatial location. Data on the performance of these cognitive tasks, urine samples, and sexual swelling over six menstrual cycles showed that the chimpanzee's performance accuracy decreased and that the intertrial interval was longer during the LH-surge of the menstrual cycle, but only for the performance of the difficult task. These performance attributes seem to reflect a decrease in attention or motivation during ovulation. In summary, the cognitive performance of a chimpanzee was disturbed by hormonal changes despite her long-term experience in the tasks.     

Calories,beauty, and ovulation: The effects of the menstrual cycle on food and appearance-related consumption

The menstrual cycle has been largely ignored within the consumer research literature. Using a survey panel, women's food and appearance-related consumption was tracked for 35 consecutive days. As predicted, food-related desires, dollars spent, and eating behaviors were greater during the luteal (non-fertile) phase, whereas appearance-related desires, dollars spent, and beautification behaviors increased during the fertile phase. Dollars spent on products unrelated to food or beautification were not significantly influenced by the menstrual cycle. Hence, women's consumption desires, preferences, and dollars spent in evolutionarily relevant product categories (food and mating) fluctuate across their ovulatory cycle. Branding-related implications are briefly discussed.     

Temporal lobe signs and reports of subjective paranormal experiences in a normal population: a replication

Correlations (r = 0.50) were found between the numbers of different psi (paranormal) experiences and the numbers of temporal lobe signs within a population of university students (n = 99). The strongest correlation of 0.60 occurred with a cluster of signs that are similar to symptoms reported by patients who show chronic foci in the mesiobasal temporal lobe. However, there were no significant correlations between numbers of different psi experiences and clusters of control items or a lie scale. Specific analyses of the 140 items of the inventory indicated only 23 reached statistical criterion (p less than .001). Of these 17 were direct temporal lobe signs that implied deepened affect, auditory-vestibular experiences (vibrations, hearing one's name called), olfactory auras, perseveration ("forced" thinking), depersonalization, and sense of the personal. Five items involved beliefs about exotic phenomena or philosophical ideas. Only one item was from a control cluster. These results support the hypothesis that mystical or paranormal experiences are associated with transient electrical foci within the temporal lobe of the human brain. The repeated occurrence of these experiences within normal individuals may be embedded within a more complex symptomatology of temporal lobe signs.