Giorgio Vallortigara

Da Euclide ai neuroni. La geometria nel cervello

Andras Csillag

Gergely Zachar

Animals living in groups are often linked to group or family members stronger than to other conspecifics, and form stronger coalitions (often based on genetic relatedness) within such groups. Effective cooperation within a group requires the preference for proximity of group members, suppression of aggression toward conspecifics, an ability to perceive and respond to social signals and to change (often synchronize) behavior accordingly. Birds have long been used for a number of investigations involving sensory perception, learning, feeding strategies and vocal communication. Recently, they have been proposed as ideal model species even for psychiatric disorders affecting social cohesion, such as autism spectrum disorder. The physiological mechanisms and neural systems underlying different forms of sociability (sexual and parental bonding, group preference, nesting, care for offspring, migration) can often be studied easier in birds, since their social behavioral repertoire, as a taxon (but sometimes also as individuals), is more diverse than that of mammals. By contrast with laboratory rodents, birds rely less on olfactory cues. Rather, they tend to use visual and acoustic signals for social interactions, much like humans. Comparative approach and evolutionary relevance of studies using avian species have already yielded valuable results in several fields of neuroscience: learning and memory (imprinting), acoustic communication (birdsong), neurogenesis (seasonal changes in the song network). With the advent of robust novel methods in molecular biology, genomics and proteomics, information technology and electronic engineering; and also based upon an ever improving battery of behavioral tests, avian research in social cohesion has likely gained a new impetus.

Avian Models for Social Cohesion

"Based on his decades of experience working with newborn chicks and other species, Vallortigara gives us a clear and accessible account of behaviors that are considered to be innate or instinctive"--

Imprinting and the Origins of Knowledge

Born Knowing

An expert on the brain argues that the mind is not a blank slate and that much early behavior is biologically predisposed rather than learned. Why do newborns show a preference for a face (or something that resembles a face) over a nonface-like object? Why do baby chicks prefer a moving object to an inanimate one? Neither baby human nor baby chick has had time to learn to like faces or movement. In Born Knowing, neuroscientist Giorgio Vallortigara argues that the mind is not a blank slate. Early behavior is biologically predisposed rather than learned, and this instinctive or innate behavior, Vallortigara says, is key to understanding the origins of knowledge. Drawing on research carried out in his own laboratory over several decades, Vallortigara explores what the imprinting process in young chicks, paralleled by the cognitive feats of human newborns, reveals about minds at the onset of life. He explains that a preference for faces or representations of something face-like and animate objects--predispositions he calls "life detectors"--streamlines learning, allowing minds to avoid a confusing multiplicity of objects in the environment, and he considers the possibility that autism spectrum disorders might be linked to a deficit in the preference for the animate. He also demonstrates that animals do not need language to think, and that addition and subtraction can be performed without numbers. The origin of knowledge, Vallortigara argues, is the wisdom that humans and animals possess as basic brain equipment, the product of natural history rather than individual development.

Secondo molti studiosi la coscienza sarebbe legata alla quantità e alla complessità degli elementi del sistema nervoso. Sulla scorta di nuovi dati emersi dagli studi sulle capacità cognitive degli organismi dotati di cervelli miniaturizzati, come ad esempio le api o le mosche, Giorgio Vallortigara sviluppa in questo libro affascinante una prospettiva minimalista antitetica a quella convinzione. Distaccandosi dai modelli oggi più comuni nell’ambito delle neuroscienze e della filosofia della mente, egli avanza la tesi originale che le forme basilari dell’attività cognitiva non abbiano bisogno di grandi cervelli, e che il surplus neurologico che si osserva in alcuni animali, tra cui gli esseri umani, sia al servizio dei magazzini di memoria e non dei processi del pensiero o della coscienza. Il substrato più plausibile per l’insorgere di quest’ultima va piuttosto ricercato in una caratteristica essenziale delle cellule, la capacità di sentire. Una capacità che si sarebbe manifestata per la prima volta quando, con l’acquisizione del movimento volontario, gli organismi elementari hanno avvertito la necessità di distinguere tra la stimolazione prodotta dalla propria attività e quella procurata dal mondo esterno, l’altro da sé. L’esistenza di un minimo comune denominatore tra noi e le forme di vita più umili ci allontana una volta di più dal concetto cartesiano dell’animale-macchina – e solleva interrogativi etici ai quali non potremo a lungo sottrarci.

Pensieri della mosca con la testa storta

Nicla Panciera

Vallortigara e Panciera ci illustrano la differenza tra le due modalità, «continua» e «discreta», che caratterizzano «il senso del numero»: tra una computazione approssimativa (condivisa da tutti gli animali) e una più precisa e arbitraria (presente quasi solo nell’uomo). E dopo aver dispiegato prove sperimentali su un ventaglio sorprendente di specie – come i pulcini, che compiono operazioni aritmetiche «naturalmente e automaticamente» –, risalgono al passaggio evolutivo che ha portato il Sapiens all’elaborazione dei numeri astratti e a quel «salto simbolico» utile in principio per gestire lo scambio e il commercio e asceso via via alle vertiginose complessità formali e concettuali della matematica teorica.

Cervelli che contano

I. C. McManus

Michael Nicholls

Left-handers have been described as "a people without a history". This special issue provides scholarly analyses of aspects of asymmetry in history, from the Renaissance to the 20th Century. Lauren Harris presents three studies describing: An 1811 American child-care manual for parents fearing, "lest their children should be left-handed"; Manuals on swordsmanship from the Renaissance onwards describing the "accepted minority" of left-handed swordsmen, a minority that still dominates the Olympics; The enigmatic bias whereby parents use their left arm to carry babies; Janet Snowman and Stephen Christman present two papers on left-handed musical geniuses: William Crotch, the self-taught, 18th Century, musical prodigy, whose unconventional left-handed playing styles stimulate many questions about the asymmetries of stringed instruments; Jimi Hendrix, the 20th Century, left-handed, guitarist of whom Robert Krieger said, "âe¦ he was just so different. He just came from such a left-field place." Chris McManus, Richard Rawles, James Moore and Matthew Freegard describe an early BBC TV programme presented in 1953 by Jacob Bronowski on right and left-handedness. In an early example of viewer participation, 6000 people sent postcards describing their handedness and also their perceptions of a "mystery picture", that was the duck-rabbit figure from Wittgensteinâe(tm)s recently published Philosophical Investigations. Chris McManus and Janet Snowman describe A left-handed compliment, a newly discovered lithograph by John Lewis Marks (ca. 1795-6 - ca. 1857-61). Given Marksâe(tm),"seeming love of vulgarity for its own sake", there is probably an obscene sub-text reminiscent of a Donald McGill postcard.

A Special Issue of Laterality

The Right Hand and the Left Hand of History

Richard J. Andrew

Lesley J. Rogers

Discusses brain asymmetry from four perspectives - function, evolution, development and causation - covering a wide range of species, including humans.

Giorgio Vallortigara

Books

Your next favorite book is out there