domingo, 23 de junio de 2013

In the Light of Evolution VII: The Human Mental Machinery

Como todos los años, esta semana asada ha sido publicado el colloquium "In the light of Evolution" en PNAS, y este año está dedicado a la evolución de la mente, con especial interés en las funciones más esquivas, como la teoría de la mente, la autoconciencia (self-awareness) o lo que se ha denominado el 'problema difícil', la memoria episódica... Podéis encontrar la lista completa y el acceso gratuito a todos ellos aquí: In the Light of Evolution VII: The Human Mental Machinery

Os dejo una lista de los abstracts de los artículos que creo que son más interesantes:

Theory of mind and Darwin’s legacy. John Searle. PNAS 2013 110 (Supplement 2) 10343-10348; published ahead of print June 10, 2013, doi:10.1073/pnas.1301214110
We do not have an adequate theory of consciousness. Both dualism and materialism are mistaken because they deny consciousness is part of the physical world. False claims include (i) behaviorism, (ii) computationalism, (iii) epiphenomenalism, (iv) the readiness potential, (v) subjectivity, and (vi) materialism. Ontological subjectivity does not preclude epistemic objectivity. Observer relative phenomena are created by consciousness, but consciousness is not itself observer relative. Consciousness consists of feeling, sentience, or awareness with (i) qualitativeness, (ii) ontological subjectivity, (iii) unified conscious field, (iv) intentionality, and (v) intentional causation. All conscious states are caused by lower level neurobiological processes in the brain, and they are realized in the brain as higher level features. Efforts to get a detailed scientific account of how brain processes cause consciousness are disappointing. The Darwinian revolution gave us a new form of explanation; two levels were substituted: a causal level, where we specify the mechanism by which the phenotype functions, and a functional level, where we specify the selectional advantage that the phenotype provides. Sociobiology attempted to explain general features of human society, ethics, etc. It failed. For the incest taboo, it confuses inhibition with prohibition. It did not explain the moral force of the taboo. To explain the function of consciousness we cannot ask, “What would be subtracted if we subtracted consciousness but left everything else the same?” We cannot leave everything else the same because consciousness is necessary for higher functions of human and animal life. The unified conscious field gives the organism vastly increased power.

Affiliation, empathy, and the origins of theory of mind. Robert M. Seyfarth and Dorothy L. Cheney. PNAS 2013 110 (Supplement 2) 10349-10356; published ahead of print June 10, 2013, doi:10.1073/pnas.1301223110
To understand the evolution of a Theory of Mind, we need to understand the selective factors that might have jumpstarted its initial evolution. We argue that a subconscious, reflexive appreciation of others’ intentions, emotions, and perspectives is at the roots of even the most complex forms of Theory of Mind and that these abilities may have evolved because natural selection has favored individuals that are motivated to empathize with others and attend to their social interactions. These skills are adaptive because they are essential to forming strong, enduring social bonds, which in turn enhance reproductive success. We first review evidence from both humans and other animals indicating that reflexive and reflective mental state attributions are inextricably linked and play a crucial role in promoting affiliative social bonds. We next describe results from free-ranging female baboons showing that individuals who show high rates of affiliative behavior form stronger social bonds with other females. These bonds, in turn, are linked to fitness. We then provide data from three different types of social challenges (male immigration, changes in grooming behavior after the death of a close relative, and responses during playback experiments), suggesting that females who manifest high rates of affiliative behavior may also be more motivated to anticipate challenges, react adaptively to setbacks, and respond appropriately to social interactions.

Evolution of consciousness: Phylogeny, ontogeny, and emergence from general anesthesia. George A. Mashour and Michael T. Alkire. PNAS 2013 110 (Supplement 2) 10357-10364; published ahead of print June 10, 2013, doi:10.1073/pnas.1301188110
Are animals conscious? If so, when did consciousness evolve? We address these long-standing and essential questions using a modern neuroscientific approach that draws on diverse fields such as consciousness studies, evolutionary neurobiology, animal psychology, and anesthesiology. We propose that the stepwise emergence from general anesthesia can serve as a reproducible model to study the evolution of consciousness across various species and use current data from anesthesiology to shed light on the phylogeny of consciousness. Ultimately, we conclude that the neurobiological structure of the vertebrate central nervous system is evolutionarily ancient and highly conserved across species and that the basic neurophysiologic mechanisms supporting consciousness in humans are found at the earliest points of vertebrate brain evolution. Thus, in agreement with Darwin’s insight and the recent “Cambridge Declaration on Consciousness in Non-Human Animals,” a review of modern scientific data suggests that the differences between species in terms of the ability to experience the world is one of degree and not kind.

Evolution of working memory. Peter Carruthers. PNAS 2013 110 (Supplement 2) 10371-10378; published ahead of print June 10, 2013, doi:10.1073/pnas.1301195110
Working memory (WM) is fundamental to many aspects of human life, including learning, speech and text comprehension, prospection and future planning, and explicit “system 2” forms of reasoning, as well as overlapping heavily with fluid general intelligence. WM has been intensively studied for many decades, and there is a growing consensus about its nature, its components, and its signature limits. Remarkably, given its central importance in human life, there has been very little comparative investigation of WM abilities across species. Consequently, much remains unknown about the evolution of this important human capacity. Some questions can be tentatively answered from the existing comparative literature. Even studies that were not intended to do so can nonetheless shed light on the WM capacities of nonhuman animals. However, many questions remain.

The evolution of episodic memory. Timothy A. Allen and Norbert J. Fortin. PNAS 2013 110 (Supplement 2) 10379-10386; published ahead of print June 10, 2013, doi:10.1073/pnas.1301199110
One prominent view holds that episodic memory emerged recently in humans and lacks a “(neo)Darwinian evolution” [Tulving E (2002) Annu Rev Psychol 53:1–25]. Here, we review evidence supporting the alternative perspective that episodic memory has a long evolutionary history. We show that fundamental features of episodic memory capacity are present in mammals and birds and that the major brain regions responsible for episodic memory in humans have anatomical and functional homologs in other species. We propose that episodic memory capacity depends on a fundamental neural circuit that is similar across mammalian and avian species, suggesting that protoepisodic memory systems exist across amniotes and, possibly, all vertebrates. The implication is that episodic memory in diverse species may primarily be due to a shared underlying neural ancestry, rather than the result of evolutionary convergence. We also discuss potential advantages that episodic memory may offer, as well as species-specific divergences that have developed on top of the fundamental episodic memory architecture. We conclude by identifying possible time points for the emergence of episodic memory in evolution, to help guide further research in this area.

Neuroethology of primate social behavior. Steve W. C. Chang, Lauren J. N. Brent, Geoffrey K. Adams, Jeffrey T. Klein, John M. Pearson, Karli K. Watson, and Michael L. Platt. PNAS 2013 110 (Supplement 2) 10387-10394; published ahead of print June 10, 2013, doi:10.1073/pnas.1301213110
A neuroethological approach to human and nonhuman primate behavior and cognition predicts biological specializations for social life. Evidence reviewed here indicates that ancestral mechanisms are often duplicated, repurposed, and differentially regulated to support social behavior. Focusing on recent research from nonhuman primates, we describe how the primate brain might implement social functions by coopting and extending preexisting mechanisms that previously supported nonsocial functions. This approach reveals that highly specialized mechanisms have evolved to decipher the immediate social context, and parallel circuits have evolved to translate social perceptual signals and nonsocial perceptual signals into partially integrated social and nonsocial motivational signals, which together inform general-purpose mechanisms that command behavior. Differences in social behavior between species, as well as between individuals within a species, result in part from neuromodulatory regulation of these neural circuits, which itself appears to be under partial genetic control. Ultimately, intraspecific variation in social behavior has differential fitness consequences, providing fundamental building blocks of natural selection. Our review suggests that the neuroethological approach to primate behavior may provide unique insights into human psychopathology.

Making lasting memories: Remembering the significant. James L. McGaugh. PNAS 2013 110 (Supplement 2) 10402-10407; published ahead of print June 10, 2013, doi:10.1073/pnas.1301209110
Although forgetting is the common fate of most of our experiences, much evidence indicates that emotional arousal enhances the storage of memories, thus serving to create, selectively, lasting memories of our more important experiences. The neurobiological systems mediating emotional arousal and memory are very closely linked. The adrenal stress hormones epinephrine and corticosterone released by emotional arousal regulate the consolidation of long-term memory. The amygdala plays a critical role in mediating these stress hormone influences. The release of norepinephrine in the amygdala and the activation of noradrenergic receptors are essential for stress hormone-induced memory enhancement. The findings of both animal and human studies provide compelling evidence that stress-induced activation of the amygdala and its interactions with other brain regions involved in processing memory play a critical role in ensuring that emotionally significant experiences are well-remembered. Recent research has determined that some human subjects have highly superior autobiographic memory of their daily experiences and that there are structural differences in the brains of these subjects compared with the brains of subjects who do not have such memory. Understanding of neurobiological bases of such exceptional memory may provide additional insights into the processes underlying the selectivity of memory.

Justice- and fairness-related behaviors in nonhuman primates. Sarah F. Brosnan. PNAS 2013 110 (Supplement 2) 10416-10423; published ahead of print June 10, 2013, doi:10.1073/pnas.1301194110
A distinctive feature across human societies is our interest in justice and fairness. People will sometimes invest in extremely costly behavior to achieve fair outcomes for themselves and others. Why do people care so much about justice? One way to address this is comparatively, exploring behaviors related to justice and fairness in other species. In this paper, I review work exploring responses to inequity, prosocial behavior, and other relevant behaviors in nonhuman primates in an effort to understand both the potential evolutionary function of these behaviors and the social and ecological reasons for the individual differences in behavior. I also consider how these behaviors relate to human behavior, particularly in the case of experimental studies using games derived from experimental economics to compare nonhuman primates’ responses to those of humans in similar experimental conditions. These results emphasize the importance of a comparative approach to better understand the function and diversity of human behavior.

From perception to pleasure: Music and its neural substrates. Robert J. Zatorre and Valorie N. Salimpoor. PNAS 2013 110 (Supplement 2) 10430-10437; published ahead of print June 10, 2013, doi:10.1073/pnas.1301228110
Music has existed in human societies since prehistory, perhaps because it allows expression and regulation of emotion and evokes pleasure. In this review, we present findings from cognitive neuroscience that bear on the question of how we get from perception of sound patterns to pleasurable responses. First, we identify some of the auditory cortical circuits that are responsible for encoding and storing tonal patterns and discuss evidence that cortical loops between auditory and frontal cortices are important for maintaining musical information in working memory and for the recognition of structural regularities in musical patterns, which then lead to expectancies. Second, we review evidence concerning the mesolimbic striatal system and its involvement in reward, motivation, and pleasure in other domains. Recent data indicate that this dopaminergic system mediates pleasure associated with music; specifically, reward value for music can be coded by activity levels in the nucleus accumbens, whose functional connectivity with auditory and frontal areas increases as a function of increasing musical reward. We propose that pleasure in music arises from interactions between cortical loops that enable predictions and expectancies to emerge from sound patterns and subcortical systems responsible for reward and valuation.

martes, 18 de junio de 2013

La antropología del "Jodo, ko!"

Por fin he terminado los exámanes de antropología, y comienzo de nuevo la lectura de papers y libros por mi cuenta hasta la siguiente tanda. Entre los papers que he encontrado me ha llamado la atención uno en concreto:

Jorgensen, Annette,  "Spanish teenage language and the COLAm corpus", Bergen Language and Linguistics Studies (2013).

En primer lugar me pareció curioso que la universidad de Bergen en Noruega se interese por el lenguaje de los jóvenes españoles. En segundo lugar, tras algunas asignaturas de antropología ligüistica me apetecía leer algo de esta rama, así que era un buen comienzo.

El artículo comienza presentando el COLAm, un corpus de datos de conversaciones de jóvenes madrileños. El estudio de esta variedad social (diastrática) de la lengua estándar basa su interés en que son los jóvenes quienes introducen más variaciones en el lenguaje, las cuales son adquiridas con posterioridad por otros sectores sociales y son una de las mayores contribuciones a la evolución del lenguaje.

Cada variedad del lenguaje se distingue por unas características que son las que en el artículo llaman el tatuaje de la lengua. Entre las características del lenguaje de los jóvenes el artículo habla de las siguiente:

- Exageración y rodeos: 

Un ejemplo del primero sería la siguiente conversación extraída del corpus COLAm:
Sara: vale, pero el culo justamente que lo tengo como una mesa camilla 
Olga:  ¿qué dices, tía? 
Sara: es como un pueblo mi culo, tía! (MAORE2J01)
Y un ejemplo del segundo sería:
cuando en plan me saca de mis casillas
- El uso de vocativos: 
Estos serían los típicos "tío", "co", "neng", "macho", "tronco", etc.

- Creaciones léxicas y anglicismos.
El artículo pone el ejemplo de la palabra "flipar" como una adopción de un anglicismo (flip).

- Palabras tabú y palabrotas: 
Aquí es interesante el ejemplo que sale en el artículo:
Me cago en tu puta madre
En esta frase se estarían usando tabús sexuales, sociales y escatológicos.

En resumen, el uso de estas estrategias lingüisticas se motivaría por la falta de confianza de los jóvenes en sí mismos, la necesidad de aceptación por el grupo y la falta de escalas de grises en los juicios que hacen de los acontecimientos.

Es un buen ejemplo de pragmática ligüistica, especialmente cognitiva, desde un punto funcionalista y a la vez desde el estudio de la variación de la lengua entre distintos estratos sociales, en este caso por edad.

La próxima vez que escuche un "ayer se quedó chaval flipado porque están mazo de guapos son dos
mensajes tronco que se los escribí pero no se los he mandado" (frase sacada del artículo) será cuestión de echar oreja y aprender un poco de lingüística en el campo.

ResearchBlogging.orgJorgensen, Annette (2013). Spanish teenage language and the COLAm corpus Bergen Language and Linguistics Studies