The pleasures of sensation.

Abstract

That the senses are the channels of communication between the external environment and the nervous system is so much a truism that, except for those who espouse ESP, the senses are held to be the sole mediators of transactions between the organism and its environment. But students of the senses tend to emphasize primarily the nature of their information handling function, their discriminative capacities and limits as well as the physiological processes upon which they are based. Behavior theorists have given heed to such function in another context when they speak of the cue function of stimuli. According to these conceptions discriminative stimuli serve to steer behavior, to guide it or set the stage for the response. But in this paper I do not plan to elaborate upon such processes. Rather I wish to call attention to certain other aspects of sensory function.In recent years, neurophysiologists have emphasized that sensory systems may mediate important functions other than discrimination. Attention has been focused on such generalized effects as arousal or alerting of the nervous system as a whole. Bremer (1935) first showed that a state of cerebral somnolence could be produced in experimental animals in which the cerebrum had been surgically isolated from the brainstem and its incoming afferent pathways. He attributed this to the interruption of sensory influx itself. Later analysis (Magoun, 1958

The gustatory neocortex of the rat

“…The first test series was a four-taste test (Days 8-12) which served to familiarize the rats with the taste qualities and provided preliminary measures of taste reactivity when the rats were relatively naive. To assess changes over time, additional four-taste tests were conducted, as shown in Table I represent a broad range of responses in normal rats (Pfaffmann, 1960) from near threshold to clear rejections for each taste (see Table 2). ' The presentation of each set of concentrations for a particular taste was such that all concentrations were presented to each group of rats on anyone day, two rats per concentration per group.…”

“…During the two decades following Patton's review, work associated largely with Pfaffmann's laboratories (e.g., Pfaffmann, 1959Pfaffmann, , 1960Pfaffmann, , 1965Pfaffmann, , 1970 led to substantial development of a basic understanding ance conditioning procedure was employed using electric shock as the aversive stimulus (Benjamin, 1960), likely involvement of the GN in taste learning and memory processes had not been addressed. In fact, prior to about 1970, there were essentially no systematic studies of the role of forebrain gustatory systems in the cognitive processing (learning and memory) of taste stimuli.…”

Ingestão de substancias doces: manutenção do equilíbrio homeostático ou pelo prazer do gosto?

“…Parece claro que o valor reforçador dessa solução é capaz de manter a freqüência desse comportamento. Todavia, um aumento do estado de motivação de um organismo para a busca de certos reforçadores, -de acordo com as teorias de motiva ção -, está ligado a operações de privação (YOUNG, 1966;PFAFFMANN, 1960;MILLENSON, 1975;SKINNER, 1938;MORGAN 1973;ROBSON, 1977;SCHMIDT, 1980). Com efeito, os animais privados deste experimento apre sentaram freqüência de respostas superior à de animais não privados, concordando, assim, com esses dados da literatura sobre a privação.…”

Chemesthesis, Thermogenesis, and Nutrition

“…The distinctive taste shared by saccharin, sucrose and glucose was once regarded as the key to scientific theory of food and water intake, its neuroscience and its societal roles (Pfaffmann, 1960(Pfaffmann, , 1964Pfaffmann, Norgren & Grill, 1977). The blowfly's consumption of sugar provided an impressively simple model (Dethier, 1962).…”