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Teleost telencephalic involvement with habituation of arousal responses
233 the same pattern. The number of correct responses dropped to chance level when the S- was exchanged and remained above c r i t e r i o n when the S+ was exchanged f or a meaningless pattern. Showing that in the two-choice visual discrimination box we used, in which water was used as reward, the position of the S- determines the choice.
INFORMATION PROCESSING IN THE TASTE PATHWAYSAND ITS BEHAVIOURALSIGNIFICANCE ROLLS, E.T. AND YAXLEY, S. Oxford Un i v e rs i t y , Department of Experimental Psychology, Oxford, England F i r s t , analysis of the a c t i v i t y of 360 single neurons in the gustatory pathways in primates (cynomolgus monkeys) showed that the tuning of neurons becomes sharper as information progresses I through the taste system. For example, the breadth of tuning to the four prototypical stimuli 1.0M glucose, 1.0M NaCl, O.O01M quinine HCI and O.01M HCl, and 20% blackcurrant j u i c e , of neurons in the f i r s t
central r e l a y , the nucleus of the s o l i t a r y t r a c t was 0.87 + 0.01 (mean + sd), 0.67 + 0.02
in the f r o n t a l opercular (primary) taste cortex, 0.56 + 0.03 in the insular tast cortex, and 0.39 + 0.23 in a new caudolateral o r b i t o f r o n t a l cortex (secondary) taste area. Second, i t was found that feeding the monkey to s a t i e t y with glucose had no e f f e c t on gustatory responses of neurons in the nucleus of the s o l i t a r y t r a c t , the f r o n t a l opercular taste cortex or the insular taste cortex, but decreased the magnitude of the neuronal responses of o r b i t o f r o n t a l cortex taste neurons which responded to glucose to zero. Third, the responses of o r b i t o f r o n t a l cortex taste neurons were shown to decrease to
food
on which the monkey was fed to s a t i e t y , but to continue to foods which had not
j u s t been eaten, that is they r e fl e c t e d sensory-specific s a t i e t y . I t is porposed that tuning becomes sharper in the taste system through unimodal processing stages so that a f t e r t h i s processing, assoc i a t i o n s can be made to other modalities with minimal interference in an association memory, and s a t i e t y can operate with some s p e c i f i c i t y , allowing responses to foods eaten to decrease without producing a decrease in responsiveness to other gustatory stimuli 2 REFERENCES I.
Smith D.V. and Travers, J.B., Chem. Senses, 4 (1979) 215-229.
2.
Rolls, E.T. In: J.-P. Changeux and M. Konishi (Eds.) Neural and Molecular Mechanisms of Learning, Springer-Verlag, B e r l i n , 1986.
TELEOST TELENCEPHALIC INVOLVEMENTWITH HABITUATION OF AROUSAL RESPONSES ROONEY, D.J. AND LAMING, P.R. Department of Zoology, The Queen's University of B e l f a s t , Belfast BT7 INN, Northern Ireland The behavioural arousal response of t e l e o s t f i s h to novel or b i o l o g i c a l l y s i g n i f i c a n t s t imuli is accompanied by consistent q u a n t i f i a b l e physiological changes of cardiac and v e n t i l a t o r y decelerations and a decrease in flow in visceral blood vessels. Response habituation on repeated stimulus present a t i o n can thus be accurately monitored. Habituation of both the behavioural and physiological correlates of the arousal response to tap or visual stimuli is severely impaired by telencephalic a b l a t i o n .
234 Lesion studies have l o c a l i z e d the telencephalic areas involved as being the posterior Dm/Dc regions. Lesions a n t e r i o r to the a n t e r i o r commissure or extensive removal of the DI region had l i t t l e
effect
on response habituation. The t e l e o s t telencephalon though important is not the sole mediator of hab i t u a t i o n , however, as lesions in i t or i t s t o t a l ablation does not t o t a l l y remove the a b i l i t y
to
habituate arousal responses.
INVOLVEMENT OF THE MONKEYHIPPOCAMPUS IN MEMORYFOR MOVEMENTS RUPNIAK, N.M.J. AND GAFFAN, D. Department of Experimental Psychology, University of Oxford, South Parks Road, Oxford OXI 3 UD, England Damage to the hippocampal system or the sulcus p r i n c i p a l i s in the f r o n t a l lobes in animals causes severe impairment in certain spatial learning tasks such as l e f t - r i g h t
a l t e r n a t i o n I , 2. The present
study investigated whether these d e f i c i t s might involve memory f o r the animals own movements by using a non-spatial visual-motor task in Macaca f a s c i c u l a r i s . The task required the monkey to learn to e i ther approach or withdraw the hand from one of two visual stimuli (A or B), but could not be solved by learning the spatial r e l a t i o n s h i p s among s t i m u l i . Rewards f o r the correct response were delivered in a single spatial l o c a t i o n . Transection of the f o r n i x , but not b i l a t e r a l ablation of the sulcus p r i n c i p a l i s , severely impaired learning of 10 such problems using novel A and B s t i m u l i . The role of the hippocampus in spatial tasks may be concerned with the control of movements rather than with the a c q u i s i t i o n of map-like knowledge of the environment. In contrast, sulcus p r i n c i p a l i s ablation may impair the use of kinaesthetic cues rather than selection of the appropriate motor response. REFERENCES I.
Olton, D.S. and Isaacson, R.L., Physiol. Behav., 3 (1968) 719-724.
2.
Mishkin, M., J. Neurophysiol., 20 (1957) 615-622.
ARE CHANGED REINFORCEMENTMECHANISMSTHE KEY FOR UNDERSTANDINGSOME OF THE BEHAVIOURAL PROBLEMSOF CHILDREN WITH MBO/ADD? SAGVOLDEN, T., WULTZ, B., MORKRID, L. AND SAEBO, S. I n s t i t u t e of Neurophysiology and I n s t i t u t e of Physiology, University of Oslo, Oslo, Norway Children with minimal brain dysfunction (MBD) / a t t e n t i o n d e f i c i t disorder (ADD) are to various degrees s u f f e r i n g from perceptual problems, a t t e n t i o n d e f i c i t s ,
impulsiveness, clumsiness and hyper-
a c t i v i t y . However, there are large i n d i v i d u a l differences. As one part of a comparative research programme, we have disigned a non-verbal a t t e n t i o n test ( a video game) where the target event (the appearance of a monster's face among some trees) occurs b r i e f l y every 30 seconds. Most c h i l d r e n need very l i t t l e c h i l d finds out by i t s e l f
i n s t r u c t i o n in order to play t h i s game. The
that he/she needs to press one button in order to observe whether or not
the face has (re) appeared and to press another button in order to make the face explode. During some parts of the t e s t , every press produces a response feedback (a picture with or without a face
INFORMATION PROCESSING IN THE TASTE PATHWAYSAND ITS BEHAVIOURALSIGNIFICANCE ROLLS, E.T. AND YAXLEY, S. Oxford Un i v e rs i t y , Department of Experimental Psychology, Oxford, England F i r s t , analysis of the a c t i v i t y of 360 single neurons in the gustatory pathways in primates (cynomolgus monkeys) showed that the tuning of neurons becomes sharper as information progresses I through the taste system. For example, the breadth of tuning to the four prototypical stimuli 1.0M glucose, 1.0M NaCl, O.O01M quinine HCI and O.01M HCl, and 20% blackcurrant j u i c e , of neurons in the f i r s t
central r e l a y , the nucleus of the s o l i t a r y t r a c t was 0.87 + 0.01 (mean + sd), 0.67 + 0.02
in the f r o n t a l opercular (primary) taste cortex, 0.56 + 0.03 in the insular tast cortex, and 0.39 + 0.23 in a new caudolateral o r b i t o f r o n t a l cortex (secondary) taste area. Second, i t was found that feeding the monkey to s a t i e t y with glucose had no e f f e c t on gustatory responses of neurons in the nucleus of the s o l i t a r y t r a c t , the f r o n t a l opercular taste cortex or the insular taste cortex, but decreased the magnitude of the neuronal responses of o r b i t o f r o n t a l cortex taste neurons which responded to glucose to zero. Third, the responses of o r b i t o f r o n t a l cortex taste neurons were shown to decrease to
food
on which the monkey was fed to s a t i e t y , but to continue to foods which had not
j u s t been eaten, that is they r e fl e c t e d sensory-specific s a t i e t y . I t is porposed that tuning becomes sharper in the taste system through unimodal processing stages so that a f t e r t h i s processing, assoc i a t i o n s can be made to other modalities with minimal interference in an association memory, and s a t i e t y can operate with some s p e c i f i c i t y , allowing responses to foods eaten to decrease without producing a decrease in responsiveness to other gustatory stimuli 2 REFERENCES I.
Smith D.V. and Travers, J.B., Chem. Senses, 4 (1979) 215-229.
2.
Rolls, E.T. In: J.-P. Changeux and M. Konishi (Eds.) Neural and Molecular Mechanisms of Learning, Springer-Verlag, B e r l i n , 1986.
TELEOST TELENCEPHALIC INVOLVEMENTWITH HABITUATION OF AROUSAL RESPONSES ROONEY, D.J. AND LAMING, P.R. Department of Zoology, The Queen's University of B e l f a s t , Belfast BT7 INN, Northern Ireland The behavioural arousal response of t e l e o s t f i s h to novel or b i o l o g i c a l l y s i g n i f i c a n t s t imuli is accompanied by consistent q u a n t i f i a b l e physiological changes of cardiac and v e n t i l a t o r y decelerations and a decrease in flow in visceral blood vessels. Response habituation on repeated stimulus present a t i o n can thus be accurately monitored. Habituation of both the behavioural and physiological correlates of the arousal response to tap or visual stimuli is severely impaired by telencephalic a b l a t i o n .
234 Lesion studies have l o c a l i z e d the telencephalic areas involved as being the posterior Dm/Dc regions. Lesions a n t e r i o r to the a n t e r i o r commissure or extensive removal of the DI region had l i t t l e
effect
on response habituation. The t e l e o s t telencephalon though important is not the sole mediator of hab i t u a t i o n , however, as lesions in i t or i t s t o t a l ablation does not t o t a l l y remove the a b i l i t y
to
habituate arousal responses.
INVOLVEMENT OF THE MONKEYHIPPOCAMPUS IN MEMORYFOR MOVEMENTS RUPNIAK, N.M.J. AND GAFFAN, D. Department of Experimental Psychology, University of Oxford, South Parks Road, Oxford OXI 3 UD, England Damage to the hippocampal system or the sulcus p r i n c i p a l i s in the f r o n t a l lobes in animals causes severe impairment in certain spatial learning tasks such as l e f t - r i g h t
a l t e r n a t i o n I , 2. The present
study investigated whether these d e f i c i t s might involve memory f o r the animals own movements by using a non-spatial visual-motor task in Macaca f a s c i c u l a r i s . The task required the monkey to learn to e i ther approach or withdraw the hand from one of two visual stimuli (A or B), but could not be solved by learning the spatial r e l a t i o n s h i p s among s t i m u l i . Rewards f o r the correct response were delivered in a single spatial l o c a t i o n . Transection of the f o r n i x , but not b i l a t e r a l ablation of the sulcus p r i n c i p a l i s , severely impaired learning of 10 such problems using novel A and B s t i m u l i . The role of the hippocampus in spatial tasks may be concerned with the control of movements rather than with the a c q u i s i t i o n of map-like knowledge of the environment. In contrast, sulcus p r i n c i p a l i s ablation may impair the use of kinaesthetic cues rather than selection of the appropriate motor response. REFERENCES I.
Olton, D.S. and Isaacson, R.L., Physiol. Behav., 3 (1968) 719-724.
2.
Mishkin, M., J. Neurophysiol., 20 (1957) 615-622.
ARE CHANGED REINFORCEMENTMECHANISMSTHE KEY FOR UNDERSTANDINGSOME OF THE BEHAVIOURAL PROBLEMSOF CHILDREN WITH MBO/ADD? SAGVOLDEN, T., WULTZ, B., MORKRID, L. AND SAEBO, S. I n s t i t u t e of Neurophysiology and I n s t i t u t e of Physiology, University of Oslo, Oslo, Norway Children with minimal brain dysfunction (MBD) / a t t e n t i o n d e f i c i t disorder (ADD) are to various degrees s u f f e r i n g from perceptual problems, a t t e n t i o n d e f i c i t s ,
impulsiveness, clumsiness and hyper-
a c t i v i t y . However, there are large i n d i v i d u a l differences. As one part of a comparative research programme, we have disigned a non-verbal a t t e n t i o n test ( a video game) where the target event (the appearance of a monster's face among some trees) occurs b r i e f l y every 30 seconds. Most c h i l d r e n need very l i t t l e c h i l d finds out by i t s e l f
i n s t r u c t i o n in order to play t h i s game. The
that he/she needs to press one button in order to observe whether or not
the face has (re) appeared and to press another button in order to make the face explode. During some parts of the t e s t , every press produces a response feedback (a picture with or without a face