The capacity to predict future events permits a creature to detect, model, and manipulate the causal structure of its interactions with its environment. Behavioral experiments suggest that learning is driven by changes in the expectations about future salient events such as rewards and punishments. Physiological work has recently complemented these studies by identifying dopaminergic neurons in the primate whose fluctuating output apparently signals changes or errors in the predictions of future salient and rewarding events. Taken together, these findings can be understood through quantitative theories of adaptive optimizing control.

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A Neural Substrate of Prediction and Reward

Over more than a century of research has established the fact that sleep benefits the retention of memory. In this review we aim to comprehensively cover the field of "sleep and memory" research by providing a historical perspective on concepts and a discussion of more recent key findings. Whereas initial theories posed a passive role for sleep enhancing memories by protecting them from interfering stimuli, current theories highlight an active role for sleep in which memories undergo a process of system consolidation during sleep. Whereas older research concentrated on the role of rapid-eye-movement (REM) sleep, recent work has revealed the importance of slow-wave sleep (SWS) for memory consolidation and also enlightened some of the underlying electrophysiological, neurochemical, and genetic mechanisms, as well as developmental aspects in these processes. Specifically, newer findings characterize sleep as a brain state optimizing memory consolidation, in opposition to the waking brain being optimized for encoding of memories. Consolidation originates from reactivation of recently encoded neuronal memory representations, which occur during SWS and transform respective representations for integration into long-term memory. Ensuing REM sleep may stabilize transformed memories. While elaborated with respect to hippocampus-dependent memories, the concept of an active redistribution of memory representations from networks serving as temporary store into long-term stores might hold also for non-hippocampus-dependent memory, and even for nonneuronal, i.e., immunological memories, giving rise to the idea that the offline consolidation of memory during sleep represents a principle of long-term memory formation established in quite different physiological systems.

https://www.zora.uzh.ch/id/eprint/77770/1/physiol_rev_93.pdf

About sleep's role in memory

Shows the many advances in the field of cognitive neurosciences. From the molecular level up to that of human consciousness, the contributions cover one of the most fascinating areas of science - the relationship between the structural and physiological mechanisms of the brain/nervous system.

/pdf/the-new-cognitive-neurosciences-n72o5zqocv.pdf

The new cognitive neurosciences

Human speech and birdsong have numerous parallels. Both humans and songbirds learn their complex vocalizations early in life, exhibiting a strong dependence on hearing the adults they will imitate, as well as themselves as they practice, and a waning of this dependence as they mature. Innate predispositions for perceiving and learning the correct sounds exist in both groups, although more evidence of innate descriptions of species-specific signals exists in songbirds, where numerous species of vocal learners have been compared. Humans also share with songbirds an early phase of learning that is primarily perceptual, which then serves to guide later vocal production. Both humans and songbirds have evolved a complex hierarchy of specialized forebrain areas in which motor and auditory centers interact closely, and which control the lower vocal motor areas also found in nonlearners. In both these vocal learners, however, how auditory feedback of self is processed in these brain areas is surprisingly unclear. Finally, humans and songbirds have similar critical periods for vocal learning, with a much greater ability to learn early in life. In both groups, the capacity for late vocal learning may be decreased by the act of learning itself, as well as by biological factors such as the hormones of puberty. Although some features of birdsong and speech are clearly not analogous, such as the capacity of language for meaning, abstraction, and flexible associations, there are striking similarities in how sensory experience is internalized and used to shape vocal outputs, and how learning is enhanced during a critical period of development. Similar neural mechanisms may therefore be involved.

/pdf/birdsong-and-human-speech-common-themes-and-mechanisms-39gg3m47d4.pdf

BIRDSONG AND HUMAN SPEECH: Common Themes and Mechanisms

New cognitive neurosciences

The Role of Auditory Feedback in the Control of Vocalization in the White‐Crowned Sparrow1

ummary
1. A new deafening technique for day-old chicks of the domestic fowl is described.

2. Audiospectrographic comparisons of vocal signals were made between normal birds on the one hand and birds that had been experimentally deafened at an early age on the other. It was demonstrated that insofar as the types are concerned, the deaf birds could develop the normal repertoire and forms of vocalization. The detailed comparisons of sound structures are difficult because of individual variation and grading in the calls.

3. One adult cock was deafened to determine the effects of deafening on the maintenance of its vocal signals. The result indicated that the forms of the calls studied here remained unchanged after deafening, although some change occurred in the detailed aspect of its crowing.

4. Most vocal signals are morphologically discrete and tend to carry qualitatively different information. The quantitative aspect of environmental and motivational information is conveyed by grading of signals. Most signals can convey both types of information simultaneously. Several methods of achieving this purpose were described.

5. The fact that the birds could develop and also maintain the normal repertoire and forms of their vocal signals without auditory feedback does not necessarily mean that the forms of the various vocal signals are determined by a centrally patterned motor command, although it is the most probable mechanism. The involvement of nonauditory feedback in the control of the central motor output has not yet been excluded in this case.

Zusammenfassung
1. Eine neue Methode des operativen Ertaubens frisch geschlupfter Kuken wird beschrieben.

2. Klangspektrographische Vergleiche der Lautauserungen bei horenden und tauben Vogeln haben ergeben, das die Entwicklung des Repertoires und der Formen der Laute bei den gehorlosen Individuen normal geschehen konnte, so weit es die Lauttypen betraf. Die individuellen und die innerhalb einer Lautform vorkommenden Variationen erschweren feinere Vergleiche der Laute beider Gruppen.

3. Der Einflus des Taubwerdens auf das Erhaltenbleiben der Lautformen wurde bei einem Hahn studiert. Die hier untersuchten Lautformen blieben alle erhalten, wenn auch das spektrographische Bild in gewissen Einzelheiten etwas verandert war.

4. Die meisten Huhnerlaute sind deutlich unterscheidbar und pflegen qualitativ verschiedene Informationen zu ubertragen. Die Ubertragung der quantitativen Information uber Umgebung und Stimmung der Tiere wird durch Abstufung der Lautsignale ermoglicht. Fast alle Lautsignale konnen die beiden Informationstypen gleichzeitig geben. Einige Weisen, auf die dieser Zweck erreicht wird, werden beschrieben.

5. Die Tatsache, das die tauben Vogel alle artgemasen Laute entwickeln und bewahren konnten, beweist noch nicht endgultig das motorische Angeborensein all dieser Laute, doch ist es die wahrscheinlichste Erklarung. Das nichtakustische Ruckmeldungen die Lauterzeugung kontrollieren, ist in diesem Falle noch nicht experimentell ausgeschlossen.

The Role of Auditory Feedback in the Vocal Behavior of the Domestic Fowl1

The development of bird song has been studied in several passerine species by rearing birds in acoustic isolation (for example, Thorpe, 1961; Sauer, 1954; Messmer and Messmer, 1956). The results of these experiments vary with the species used. The development of normal vocalization without any external source of reference implies that there is an internal and inherited source of reference. There may be an inherited mechanism in the central nervous system which is responsible for “patterned” vocal motor output without any sensory feedback. Or the central nervous system may have an inherited mechanism to recognize normal vocalization as it is registered by the ear or by the pattern of proprioceptive or other nonauditory feedback. The isolation experiment alone does not discriminate between these possibilities. It is the purpose of the present work to investigate the role of audition in the development of song, using audiospectrographic analyses of the sound.

Effects of Deafening on Song Development in Two Species of Juncos

Effects of deafening on song development in American robins and black-headed grosbeaks.

Besides its contribution to the study of vocal communication, the study of song variation in natural passerine populations is of basic importance for the analyses of comparative, genetic, and developmental aspects of song, just as the study of variation is important in comparative morphology. The song of the Oregon Junco (Junco oreganus) is found to be very suitable material for such analyses, and the developmental aspect has already been considered by Marler, Kreith, and Tamura (1962) and Konishi (1964). Furthermore, with additional reports on song variation we are beginning to see some possibility of objective comparisons and of generalizations about differences between species. METHODS

Masakazu Konishi

Papers

The Role of Auditory Feedback in the Control of Vocalization in the White‐Crowned Sparrow1

The Role of Auditory Feedback in the Vocal Behavior of the Domestic Fowl1

Effects of Deafening on Song Development in Two Species of Juncos

Effects of deafening on song development in American robins and black-headed grosbeaks.

Song Variation in a Population of Oregon Juncos