Neuronal Group Selection Research Articles

Two theories of action - Edelman's Neuronal group Selection and the Poetics of Paul Valéry

Motivated by two imperatives as they are framed in Code Biology – mechanism and actualization - we have turned to other attempts of modeling life at work. Here, we present two theories devoted to minds in action – one explains neuronal function, and the other dissects poetic crafting. Neuronal networks activation and poetic composition, respectively, are seen as the selection of specific connective patterns of either neurons or words, in action. Gerald Edelman, as a scientist, has generalized the Darwinian ideas of variation and selection to the cellular level in his “Sciences of Recognition”, a broader theoretical framework that includes the “Theory of Neuronal Group Selection” (TGNS) analyzed here. Paul Valéry, as a poet, has reconciled inspiration and technique in what he has called “works of the mind”, the creative processes mediated by sensing and making sense, in the “Poetic Theory” we present here he advances the mechanisms of artistic composition. We have identified the main ideas conveyed in these two theories, i.e., variation and selection, integration and differentiation, ambiguity and degeneracy, binding and blending, stasis and semiosis, by pairing and comparing textual fragments from the authors. We show that TGNS and the Theory of Poetic Action reconcile Sciences and Arts by recognizing that Natural Selection is a mechanism implied by formative acts in both scenarios and discuss to which extent Natural Convention - the main contribution of Code Biology – is integrated by the two thinkers.

Understanding Neural Oscillations in the Human Brain: From Movement to Consciousness and Vice Versa.

Considering perinatal human maturation of the cerebral cortex, movement occurs before consciousness. Considering human motor control, consciousness endorses voluntary action. On the arduous road to understanding consciousness and its mechanisms, new and refined experimental paradigms may determine the next avenue. From this perspective, involuntary and voluntary movements can be considered the starting point of consciousness, the consequence of consciousness, or just a tool for approaching it. From the recent consciousness models including neural group selection and the integrated information theories, we highlight some of the experimental considerations that could indicate that movement frames consciousness. On the one hand, it may be a trigger for searching the key features in the environment (e.g., eye-scan path), but on the other hand it may conclude the final reporting of consciousness (e.g., goal vocal or manual-oriented action). The aim of this opinion paper is to encourage a discussion in the framework of the research topic, “Understanding Neural Oscillation in the Human Brain: Consciousness of Movement Execution,” and to promote new scientific interest about the hypothesis that movement is inescapable in understanding consciousness. In the following subsections we underline that oscillatory brain mechanisms integrate movement into the dynamics of the default mode network, the bottom up and top down modulations, the intentional actions in social contexts, the individual selfness and body identity, suggesting that movement may be essential to consciousness and that the oscillations-movement-consciousness triad should be inextricable. Before the emergence of long-range cortical connections that allow consciousness (Varela et al., 2001), the early emergence of spontaneous electrical activity in the brain is based on well-shaped intermittent spontaneous oscillations that produce fetal movements (Khazipov et al., 2004; Khazipov and Milh, 2018). In rat pups, these stochastic motor actions, which are described as “popcorn” movements, generate reafferentation activities via the thalamocortical system, allowing self-organized dynamics in the brain (Buzsaki, 2011). These immature movements allow exploration of the physic world, and finally conduct humans toward self-consciousness, for which body perception and action play an important role in elaborating a sense of self and differentiating between self and others (Keromnes et al., 2018). Recent theories about consciousness (Edelman, 2003; Seth et al., 2006; Edelman et al., 2011; Park and Blanke, 2019) have paved the way for new experimental paradigms. Thirteen features have been proposed (Seth et al., 2006) in order to better characterize the theoretical frame of reference for consciousness. Among these items, the first three established that: (1) fast, irregular, and low-amplitude oscillations (~12–70 Hz) convey consciousness; (2) these oscillatory neuronal activities are organized by the thalamocortical system acting as a “dynamic core” modulated by subcortical influences; and (3) consciousness is dispatched in different cortical areas depending on the conscious content. The other 10 items highlight that the conscious events are unitary, and that only one conscious experience emerges at a time. Accordingly, the theory of neuronal group selection (TNGS) (Edelman, 1987) is advanced as a biological foundation of consciousness. Following the TNGS, Darwinistic selection has ontogenetically shaped neuronal circuits based on positive or negative outcomes on the environment and related feedback. In this context, the reentry process linking numerous brainstem nuclei with the thalamocortical system (Edelman and Gally, 2013) and the recurrent circuit in the cortex that assumes the function of working memory (McCormick, 2001) are crucial for consciousness (Edelman et al., 2011). This implies that consciousness is a dynamic embodied process (Seth et al., 2006) that is closely related not only to voluntary movement production, but also to internal body signals from visceral organs (Park et al., 2018; Park and Blanke, 2019). Electroencephalography (EEG) (Haegens et al., 2010; Braboszcz and Delorme, 2011; Baird et al., 2014; Horschig et al., 2014; Shafto and Pitts, 2015; Koivisto et al., 2016; Ye et al., 2019) and functional magnetic resonance imaging (fMRI) (Kucyi, 2018; Kucyi et al., 2018; Demertzi et al., 2019; Golkowski et al., 2019; Liegeois et al., 2019; Yin et al., 2019) are commonly used to study general attention and consciousness in humans. Although the high temporal resolution of the EEG (timing in milliseconds range) and high spatial resolution of the fMRI (location in millimeters range) are viewed as complementary for understanding neural processes (Brechet et al., 2019; Shen et al., 2019), recent evidence (Itthipuripat et al., 2019) demonstrated that hemodynamic attentional modulations measured in the early sensory cortex are differentially related to evoked EEG potentials, as they are linked more to later than early evoked potentials.

Development Through the Lens of a Perception-Action-Cognition Connection: Recognizing the Need for a Paradigm Shift in Clinical Reasoning.

Clinical assessment of movement and posture guides the decision-making process in designing interventions for infants and children with movement disorders. Clinical reasoning is influenced by the therapist's understanding of developmental processes. The views of development grounded in perception-action, dynamic systems, and neuronal group selection theories are well recognized in current literature and supported by a large body of research. Based on the available evidence, intervention must be task-specific, repetitive, and highly salient to the child. Furthermore, it must honor spontaneous exploration and active problem-solving, enhance the child's ability to perceive environmental affordances, and target optimal variability and adaptability of movement and posture. However, a neuromaturational approach to developmental assessment and intervention that relies on "teaching" motor milestones and emphasizes the importance of correcting movement patterns in infants and children developing atypically is still prevalent in the clinic. This perspective paper will: (1) examine evidence in support of a paradigm shift from neuromaturational views toward bringing the concepts of grounded cognition, variability, complexity, and adaptability to the forefront of clinical reasoning; and (2) introduce the Perception-Action Approach as a method of assessment and intervention that may serve as an agent of such a shift by augmenting knowledge translation for the clinician.

Locomotor Training Increases Synaptic Structure With High NGL-2 Expression After Spinal Cord Hemisection

Background. We previously demonstrated that step training leads to reorganization of neuronal networks in the lumbar spinal cord of rodents after a hemisection (HX) injury and step training, including increases excitability of spinally evoked potentials in hindlimb motor neurons. Methods. In this study, we investigated changes in RNA expression and synapse number using RNA-Seq and immunohistochemistry of the lumbar spinal cord 23 days after a mid-thoracic HX in rats with and without post-HX step training. Results. Gene Ontology (GO) term clustering demonstrated that expression levels of 36 synapse-related genes were increased in trained compared with nontrained rats. Many synaptic genes were upregulated in trained rats, but Lrrc4 (coding NGL-2) was the most highly expressed in the lumbar spinal cord caudal to the HX lesion. Trained rats also had a higher number of NGL-2/synaptophysin synaptic puncta in the lumbar ventral horn. Conclusions. Our findings demonstrate clear activity-dependent regulation of synapse-related gene expression post-HX. This effect is consistent with the concept that activity-dependent phenomena can provide a mechanistic drive for epigenetic neuronal group selection in the shaping of the reorganization of synaptic networks to learn the locomotion task being trained after spinal cord injury.

Coaching in early physical therapy intervention: the COPCA program as an example of translation of theory into practice

Background: Coaching is en vogue in pediatric physiotherapy, but often applied rather unspecific and undefined.Methods: This paper aims to describe coaching in early physiotherapy intervention, taking the specific coaching approach of the family-centered program “COPing with and CAring for infants with special needs” (COPCA) as a case in point.Results: The theoretical underpinnings of coaching in COPCA, including a meta-model, family-centered practice, the Neuronal Group Selection Theory and the goal-oriented coaching approach, are discussed. Next, the translation of theory into practical ingredients for coaching of families of a child with special needs is presented. The latter includes the appreciation of family autonomy and attitudes, and the creativity to ask specific questions to support the families in making their own decisions to promote their child’s development during daily care-giving routines.Conclusion: It is concluded that the approach of coaching is demanding for both families and pediatric physiotherapists. It requires an active role of the family members in the intervention process and for therapists that they incorporate the attitude of a coach that largely differs from the attitude of the traditional therapist. For families and pediatric physiotherapists appreciating these changes in attitude, COPCA’s coaching offers a promising form of early intervention.Implications for rehabilitationWe recommend the implementation of the promising approach of goal-oriented and solution-focused coaching in pediatric rehabilitation and/or early intervention.We recommend applying coaching methods that are based on explicit theoretical background and clinical knowledge.We recommend formal training in coaching before professionals apply coaching in pediatric rehabilitation and/or early intervention.

What is Trained Develops! Theoretical Perspective on Skill Learning.

Knowledge about developmental theories is important for experts or specialists working with children following normal development and children who have various kinds of dysfunction, in order to better understand what happens with processes associated with motor behavior. In this article, we have explored how theories of development and learning can be used to understand processes associated with motor behavior. A probabilistic perspective emphasizes that the changes taking place in the development is a result of interaction: structural changes in the nervous system leading to changes in function and behavior and opposite, functional changes resulting in changes in structure. This bidirectional interaction between biological and experiential aspects is a continuous process which cannot be reduced to either organism or environment. Dynamical systems theory (DST) emphasizes that it is the interaction between the person, the environment, and the task that changes how our movements are, also in terms of how we develop and learn new movements. The interplay between these factors will, over time, lead to changes in motor development. The importance of experience is central to Edelman's theory of neuronal group selection (NGST). Activation of the nervous system increases the connections between certain areas of the brain, and the selection processes in the brain are a result of enhancement of neural connections involved in a "successful" motion. The central nervous system adapts its structure and function in response to internal and external influences, and hence neural plasticity is a prerequisite for learning and development. We argue that Edelman´s approach supports the theory of specificity of learning. From the perspectives of probabilistic epigenesis, DST, and NGST, we can see that being physically active and having the opportunity to get different movement experiences are of great significance for promoting motor development and learning. A variation of purposeful or rewarding physical activity in a variety of contexts will provide individual opportunities for changes of behavior in terms of both quantitative and qualitative changes in motor development.

Variability of Neuronal Responses: Types and Functional Significance in Neuroplasticity and Neural Darwinism.

HIGHLIGHTS We suggest classifying variability of neuronal responses as follows: false (associated with a lack of knowledge about the influential factors), “genuine harmful” (noise), “genuine neutral” (synonyms, repeats), and “genuine useful” (the basis of neuroplasticity and learning).The genuine neutral variability is considered in terms of the phenomenon of degeneracy.Of particular importance is the genuine useful variability that is considered as a potential basis for neuroplasticity and learning. This type of variability is considered in terms of the neural Darwinism theory.In many cases, neural signals detected under the same external experimental conditions significantly change from trial to trial. The variability phenomenon, which complicates extraction of reproducible results and is ignored in many studies by averaging, has attracted attention of researchers in recent years. In this paper, we classify possible types of variability based on its functional significance and describe features of each type. We describe the key adaptive significance of variability at the neural network level and the degeneracy phenomenon that may be important for learning processes in connection with the principle of neuronal group selection.

Development of artificial cognitive systems based on models of the brain of living organisms

Despite the continuous growth of our knowledge of the functioning of nervous systems and sophisticated features of the neuroanatomy and neurophysiology of various animal species, the basic mechanisms that provide for such properties as the ability to learn, use memory, recognize patterns, and learn about the world are poorly understood. In this paper, we present an overview of artificial devices that model the brain and solve such cognitive tasks as navigation, pattern recognition, routing, and target site finding. We discuss both hybrid systems (hybrots), in which living neural networks control an artificial body, and systems in which such an artificial body is controlled by computer programs based on different models of the brain and its regions (animats). Two basic types of hybrid systems are considered: those in which the robot is connected to the brain of a living body, such as a rat, and those in which information is received from neurons taken from the body or neurons cultured on a microelectrode array detecting their electrical potentials. Among the computational approaches that simulate nervous systems of living organisms, we can mark out the Darwin family of devices based on the theory of neuronal group selection (TNGS). In addition, we consider papers in which animats solve navigation tasks using different models of the rat hippocampus, based on such modeling methods as cognitive graph, view cells, place cells, and experience cells. The approaches under consideration provide researchers with new tools to analyze basic principles of neuron interaction between each other and with the outside world, the principles that provide higher brain functions.

Solving Clinical Puzzles: Memory as Relational Process

This paper offers our view of memory as relational process, a view derived both from Emmanuel Ghent's systems understanding of relational and from Gerald Edelman's biological understanding of process. Memory in our view is understood as relational rather than self-referenced and self-bound; as ongoing process rather than as static representation; as creation rather than as replication; as idiosyncratic in the moment rather than as faithful to the past; and as fluid rather than as fixed, although, as we stress, at times it in fact may feel so different, so fixed, and so faithful to the past. The defining attributes that we conceptualize offer a biological understanding of memory as it actually forms in the brain, emerging from dynamic neuronal patterns and the protein codes by which these variable patterns are set into motion. Generalizations derived from Edelman's global brain theory provide the clinician with both nomothetic and idiographic understanding of memory and its emergence in human experience. Specifically, three such nomothetic generalizations are described and then applied to case material, illustrating the importance of this biological brain-based conceptualization of memory to a more complex understanding of our patients. 1Edelman's (1990, 1992, 2004, 2006) theory of global brain function may be contrasted with the prevailing theory of brain postulated as specialized, segregated modules. This is the theory favored by the field of Neuro-Psychoanalysis, as represented in the mission statement of the inaugural issue of the Neuro-Psychoanalysis Journal (Vol. 1, 1999, pp. 3–4). Edelman's theory is an intricately developed conceptualization that in the form we present here is deceptively simple. It is important not to lose sight of the scientific grounding on which Edelman's global brain theory is premised. The theory requires for full understanding mastery of several foundational scientific premises, each of which must be articulated before his theory of consciousness as a property of brain function can be understood. It is beyond the scope of this paper to provide a full explication of these premises, but nevertheless it seems important to note them, as follows: (a) The properties of Consciousness; (b) The relevant Neuroanatomy of the brain; (c) The Darwinian principles of Evolution and Selectionism: Population Thinking; and (d) Edelman's Theory of Neuronal Group Selection, including the mechanisms of selection particular to neural networks (Edelman, 2004).

Selectionist and Evolutionary Approaches to Brain Function: A Critical Appraisal

We consider approaches to brain dynamics and function that have been claimed to be Darwinian. These include Edelman’s theory of neuronal group selection, Changeux’s theory of synaptic selection and selective stabilization of pre-representations, Seung’s Darwinian synapse, Loewenstein’s synaptic melioration, Adam’s selfish synapse, and Calvin’s replicating activity patterns. Except for the last two, the proposed mechanisms are selectionist but not truly Darwinian, because no replicators with information transfer to copies and hereditary variation can be identified in them. All of them fit, however, a generalized selectionist framework conforming to the picture of Price’s covariance formulation, which deliberately was not specific even to selection in biology, and therefore does not imply an algorithmic picture of biological evolution. Bayesian models and reinforcement learning are formally in agreement with selection dynamics. A classification of search algorithms is shown to include Darwinian replicators (evolutionary units with multiplication, heredity, and variability) as the most powerful mechanism for search in a sparsely occupied search space. Examples are given of cases where parallel competitive search with information transfer among the units is more efficient than search without information transfer between units. Finally, we review our recent attempts to construct and analyze simple models of true Darwinian evolutionary units in the brain in terms of connectivity and activity copying of neuronal groups. Although none of the proposed neuronal replicators include miraculous mechanisms, their identification remains a challenge but also a great promise.

Differences Between the Family-Centered “COPCA” Program and Traditional Infant Physical Therapy Based on Neurodevelopmental Treatment Principles

Evidence for effectiveness of pediatric physical therapy in infants at high risk for developmental motor disorders is limited. Therefore, "Coping With and Caring for Infants With Special Needs" (COPCA), a family-centered, early intervention program, was developed. The COPCA program is based on 2 components: (1) family involvement and educational parenting and (2) the neuromotor principles of the neuronal group selection theory. The COPCA coach uses principles of coaching to encourage the family's own capacities for solving problems of daily care and incorporating variation, along with trial and error in daily activities. The purpose of this study was to evaluate whether the content of sessions of the home-based, early intervention COPCA program differs from that of traditional infant physical therapy (TIP) sessions, which in the Netherlands are largely based on neurodevelopmental treatment. The study was conducted at the University Medical Center Groningen in the Netherlands. A quantitative video analysis of therapy sessions was conducted with infants participating in a 2-arm randomized trial. Forty-six infants at high risk for developmental motor disorders were randomly assigned to receive COPCA (n=21) or TIP (n=25) between 3 and 6 months corrected age. Intervention sessions were videotaped at 4 and 6 months corrected age and analyzed with a standardized observation protocol for the classification of physical therapy actions. Outcome parameters were relative amounts of time spent on specific physical therapy actions. The content of COPCA and TIP differed substantially. For instance, in TIP sessions, more time was spent on facilitation techniques, including handling, than in COPCA sessions (29% versus 3%, respectively). During COPCA, more time was spent on family coaching and education than during TIP (16% versus 4%, respectively). The major limitation of the study was its restriction to the Netherlands, implying that findings cannot be generalized automatically to other countries. The COPCA program differs broadly from TIP as applied in the Netherlands. Studies on the effectiveness of this family-centered program are needed.

Emergence of synchronicity in a self-organizing spiking neuron network: an approach via genetic algorithms

Based on the Theory of Neuronal Group Selection (TNGS), we have investigated the emergence of synchronicity in a network composed of spiking neurons via genetic algorithm. The TNGS establishes that a neuronal group is the most basic unit in the cortical area of the brain and, as a rule, it is not formed by a single neuron, but by a cluster of tightly coupled neural cells which fire and oscillate in synchrony at a predefined frequency. Thus, this paper describes a method of tuning the parameters of the Izhikevich spiking neuron model through genetic algorithm in order to enable the self-organization of the neural network. Computational experiments were performed considering a network composed of neurons of the same type and another composed of neurons of different types.

Why Children With Special Needs Feel Better with Hippotherapy Sessions: A Conceptual Review

Hippotherapy literally means "therapy with the help of a horse" and is derived from the Greek word hippos, meaning "horse." Hippocrates was the first to describe the benefits of hippotherapy for rehabilitation purposes. Although this therapy has many years of history, few scholars have defined the theoretical bases of hippotherapy and less about how psychologic, physical, social, and educational benefits can be achieved through hippotherapy in children with special needs. This article is designed from a chronological perspective to provide mental health professionals, educators, and others with current information on how horses can be used as a main tool in an effective and holistic therapy for children with special needs. This is supported by current literature review through a conceptual framework of hippotherapy explained by dynamic system theory along with the theory of neuronal group selection and sensory integration theory. Hippotherapy, by affecting multiple systems such as the sensory, muscular, skeletal, limbic, vestibular, and ocular systems simultaneously, leads to psychologic, social, and educational benefits that will be evidenced in behavioral patterns used in other environments.

Variation and Variability: Key Words in Human Motor Development

This article reviews developmental processes in the human brain and basic principles underlying typical and atypical motor development. The Neuronal Group Selection Theory is used as theoretical frame of reference. Evidence is accumulating that abundance in cerebral connectivity is the neural basis of human behavioral variability (ie, the ability to select, from a large repertoire of behavioral solutions, the one most appropriate for a specific situation). Indeed, typical human motor development is characterized by variation and the development of adaptive variability. Atypical motor development is characterized by a limited variation (a limited repertoire of motor strategies) and a limited ability to vary motor behavior according to the specifics of the situation (ie, limited variability). Limitations in variation are related to structural anomalies in which disturbances of cortical connectivity may play a prominent role, whereas limitations in variability are present in virtually all children with atypical motor development. The possible applications of variation and variability in diagnostics in children with or at risk for a developmental motor disorder are discussed.

Variability in Childhood Development

The goal of this special issue of PTJ was to gather together a set of articles focusing on several aspects of intra-individual variability during infancy and childhood. Intra-individual variability can be defined as differences in motor development or performance within individuals and between repeated measurements. The term “fluctuations” is reserved for differences among consecutive points in a variable trajectory, whereas “stability indicates the counterpart of (or the lack of) variability.”1 One of the reasons why variability in childhood development is receiving attention lies in the introduction of new theoretical viewpoints, namely dynamic systems theory and Neuronal Group Selection Theory. Thelen and Smith2 were among the first to apply the dynamic systems approach to childhood development. The dynamic approach turns variability within and between individuals into an essential element in the developmental process. Variability is considered to be the harbinger of …

Neonatal Physical Therapy. Part II: Practice Frameworks and Evidence-Based Practice Guidelines

(1) To outline frameworks for neonatal physical therapy based on 3 theoretical models, (2) to describe emerging literature supporting neonatal physical therapy practice, and (3) to identify evidence-based practice recommendations. Three models are presented as a framework for neonatal practice: (1) dynamic systems theory including synactive theory and the theory of neuronal group selection, (2) the International Classification of Functioning, Disability and Health, and (3) family-centered care. Literature is summarized to support neonatal physical therapists in the areas of examination, developmental care, intervention, and parent education. Practice recommendations are offered with levels of evidence identified. Neonatal physical therapy practice has a theoretical and evidence-based structure, and evidence is emerging for selected clinical procedures. Continued research to expand the science of neonatal physical therapy is critical to elevate the evidence and support practice recommendations.

Behavioral and neural Darwinism: Selectionist function and mechanism in adaptive behavior dynamics

An evolutionary theory of behavior dynamics and a theory of neuronal group selection share a common selectionist framework. The theory of behavior dynamics instantiates abstractly the idea that behavior is selected by its consequences. It implements Darwinian principles of selection, reproduction, and mutation to generate adaptive behavior in virtual organisms. The behavior generated by the theory has been shown to be quantitatively indistinguishable from that of live organisms. The theory of neuronal group selection suggests a mechanism whereby the abstract principles of the evolutionary theory may be implemented in the nervous systems of biological organisms. According to this theory, groups of neurons subserving behavior may be selected by synaptic modifications that occur when the consequences of behavior activate value systems in the brain. Together, these theories constitute a framework for a comprehensive account of adaptive behavior that extends from brain function to the behavior of whole organisms in quantitative detail.

Dream interpretation, affect, and the theory of neuronal group selection: Freud, Winnicott, Bion, and Modell

The author uses a dream specimen as interpreted during psychoanalysis to illustrate Modell's hypothesis that Edelman's theory of neuronal group selection (TNGS) may provide a valuable neurobiological model for Freud's dynamic unconscious, imaginative processes in the mind, the retranscription of memory in psychoanalysis, and intersubjective processes in the analytic relationship. He draws parallels between the interpretation of the dream material with keen attention to affect‐laden meanings in the evolving analytic relationship in the domain of psychoanalysis and the principles of Edelman's TNGS in the domain of neurobiology. The author notes how this correlation may underscore the importance of dream interpretation in psychoanalysis. He also suggests areas for further investigation in both realms based on study of their interplay.

Polychronization: Computation with Spikes

We present a minimal spiking network that can polychronize, that is, exhibit reproducible time-locked but not synchronous firing patterns with millisecond precision, as in synfire braids. The network consists of cortical spiking neurons with axonal conduction delays and spike-timing-dependent plasticity (STDP); a ready-to-use MATLAB code is included. It exhibits sleeplike oscillations, gamma (40 Hz) rhythms, conversion of firing rates to spike timings, and other interesting regimes. Due to the interplay between the delays and STDP, the spiking neurons spontaneously self-organize into groups and generate patterns of stereotypical polychronous activity. To our surprise, the number of coexisting polychronous groups far exceeds the number of neurons in the network, resulting in an unprecedented memory capacity of the system. We speculate on the significance of polychrony to the theory of neuronal group selection (TNGS, neural Darwinism), cognitive neural computations, binding and gamma rhythm, mechanisms of attention, and consciousness as "attention to memories."

Resonance in an exemplar-based lexicon: The emergence of social identity and phonology

Two sets of data are discussed in terms of an exemplar-resonance model of the lexicon. First, a cross-linguistic review of vowel formant measurements indicate that phonetic differences between male and female talkers are a function of language, dissociated to a certain extent from vocal tract length. Second, an auditory word recognition study [Strand (2000). Gender Stereotype Effects in Speech Processing. Ph.D. Dissertation, Ohio State University] indicates that listeners can process words faster when the talker has a stereotypical sounding voice. An exemplar-resonance model of perception derives these effects suggesting that reentrant pathways [Edelman (1987). Neural Darwinism: The theory of neuronal group selection. New York: Basic Books] between cognitive categories and detailed exemplars of them leads to the emergence of social and linguistic entities.