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When seeing with one eye is better than with two
236 WHEN SEEING WITH ONE EYE IS BETTER THAN WITH TWO COWEY, A., LAWLER, K. AND BOWN, B. Dept. of Experimental Psychology, U n i v e r s i t y of Oxford, South Parks Road, Oxford OXI 3PS, (England) The visual neglect that follows damage to the superior c o l l i c u l i known and not d i f f i c u l t
is well
to explain. The mild defects in pattern and movement
d i s c r i m i n a t i o n are more puzzling, given that the pathways from r e t i n a to s t r i a t e cortex are a l i v e and w e l l . Large c o l l i c u l a r lesions produce a curious stare, as i f the animal were p e r s i s t e n t l y looking at the horizon. I f so there should be d i p l o p i a f o r near targets. We tested t h i s and showed that monkeys with combined ablation of superior c o l l i c u l i
and f r o n t a l e y e - f i e l d s were better at l o c a l i z i n g
peanuts and at d i s c r i m i n a t i n g certain striped patterns when using one eye rather than both eyes. They were also grossly impaired at d i s c r i m i n a t i n g random dot stereograms~ as expected i f vergence is abolished or seriously degraded. F i n a l l y we tested ourselves on a movement d i s c r i m i n a t i o n task used previously to show that monkeys with c o l l i c u l a r damage have elevated movement detection thresholds. Our thresholds were s i m i l a r l y raised by gazing "through" the target at i n f i n i t y .
We propose that there is a simple motor explanation for some of the
so-called perceptual impairments that f o l l o w damage to the mid-brain visual pathways.
PERCEIVING EMOTIONAL CONDITIONS IN BRAIN DAMAGEDAND NORMAL PEOPLE DE BASTIANI, P., DI PALMA, G., MONETTI, V.C. AND PALMONARI, M.G. C l i n i c a Neurologica, Universita di Ferrara, Corso d e l l a Giovecca 203, Ferrara (Italy) C l i n i c a l and experimental evidence suggests that both the r i g h t (RH) and the l e f t hemisphere (LH) play a role in producing emotional responses, although a few reports have suggested a greater RH role in processing emotional input. This s p e c i f i c RH competance has been recently investigated by a number of authors studying the r e l a t i o n s h i p between the a f f e c t i v e components of language (prosody, emotional contours, gesturing e t c . ) and the a b i l i t y formation conveyed by these means.
to analyse i n -
is well
to explain. The mild defects in pattern and movement
d i s c r i m i n a t i o n are more puzzling, given that the pathways from r e t i n a to s t r i a t e cortex are a l i v e and w e l l . Large c o l l i c u l a r lesions produce a curious stare, as i f the animal were p e r s i s t e n t l y looking at the horizon. I f so there should be d i p l o p i a f o r near targets. We tested t h i s and showed that monkeys with combined ablation of superior c o l l i c u l i
and f r o n t a l e y e - f i e l d s were better at l o c a l i z i n g
peanuts and at d i s c r i m i n a t i n g certain striped patterns when using one eye rather than both eyes. They were also grossly impaired at d i s c r i m i n a t i n g random dot stereograms~ as expected i f vergence is abolished or seriously degraded. F i n a l l y we tested ourselves on a movement d i s c r i m i n a t i o n task used previously to show that monkeys with c o l l i c u l a r damage have elevated movement detection thresholds. Our thresholds were s i m i l a r l y raised by gazing "through" the target at i n f i n i t y .
We propose that there is a simple motor explanation for some of the
so-called perceptual impairments that f o l l o w damage to the mid-brain visual pathways.
PERCEIVING EMOTIONAL CONDITIONS IN BRAIN DAMAGEDAND NORMAL PEOPLE DE BASTIANI, P., DI PALMA, G., MONETTI, V.C. AND PALMONARI, M.G. C l i n i c a Neurologica, Universita di Ferrara, Corso d e l l a Giovecca 203, Ferrara (Italy) C l i n i c a l and experimental evidence suggests that both the r i g h t (RH) and the l e f t hemisphere (LH) play a role in producing emotional responses, although a few reports have suggested a greater RH role in processing emotional input. This s p e c i f i c RH competance has been recently investigated by a number of authors studying the r e l a t i o n s h i p between the a f f e c t i v e components of language (prosody, emotional contours, gesturing e t c . ) and the a b i l i t y formation conveyed by these means.
to analyse i n -