Cogprints: No conditions. Results ordered Title. 2018-01-17T14:22:17ZEPrintshttp://cogprints.org/images/sitelogo.gifhttp://cogprints.org/2001-08-20Z2011-03-11T08:54:46Zhttp://cogprints.org/id/eprint/1758This item is in the repository with the URL: http://cogprints.org/id/eprint/17582001-08-20ZThe reaction of monkeys to 'fearsome' picturesMonkeys, given the opportunity to look at a picture which excites both interest and fear, choose first to look at it and only later, once their interest has abated, to avoid it.Nicholas K HumphreyGraham R Keeble2001-08-30Z2011-03-11T08:54:47Zhttp://cogprints.org/id/eprint/1777This item is in the repository with the URL: http://cogprints.org/id/eprint/17772001-08-30ZSpecies and individuals in the perceptual world of monkeysWhen a monkey is given the choice of looking at a novel picture or a blank white screen he shows an initial preference for the picture which usually abates within about 200 seconds; if the picture is then changed for another his preference revives. The level of preference for the second picture depends on the degree to which it is perceived as 'similar' to or 'different' from the first. This technique has been used to investigate how rhesus monkeys classify pictures of animals, and in particular the extent to which they differentiate between individual animals of the same species. Two classes of animal pictures were used, namely pictures of other rhesus monkeys and pictures of domestic animals. The results indicate that inexperienced monkeys, to whom the domestic animals are unfamiliar, treat individual domestic animals of the same species as being closely similar; they treat individual monkeys, on the other hand, as being quite different from each other. Experienced monkeys, however, who have been exposed over the course of 6 months to many further pictures of animals, come to treat all individuals as different from each other, so that one pig, say, is now seen as being as different from another pig as is one monkey from another.Nicholas K Humphrey1998-04-25Z2011-03-11T08:53:37Zhttp://cogprints.org/id/eprint/18This item is in the repository with the URL: http://cogprints.org/id/eprint/181998-04-25ZThree modes of repetitive firing and the role of threshold time course between spikes.When rhythmic firing is elicited in cat spinal motoneurons by long-lasting depolarizing currents, the 'threshold' voltage from which each spike arises may appear to be quite constant (Fig. 1A, arrow). If one probes for the threshold during the interspike interval (ISI), however, it is seen to fall well below this level, rising towards it later in the ISI. Exceptionally large depolarizing afterpotentials may intersect this threshold time course shortly after a spike, causing an extra spike. The extra spike itself may also similarly produce another extra spike; thus a regenerative cycle may produce a burst of spikes at a high firing rate.William H Calvin2001-08-20Z2011-03-11T08:54:46Zhttp://cogprints.org/id/eprint/1757This item is in the repository with the URL: http://cogprints.org/id/eprint/17572001-08-20ZVision in a monkey without striate cortex: a case studyA rhesus monkey, Helen, from whom the striate cortex was almost totally removed, was studied intensively over a period of 8 years. During this time she regained an effective, though limited, degree of visually guided behaviour. The evidence suggests that while Helen suffered a permanent loss of 'focal vision' she retained (initially unexpressed) the capacity for 'ambient vision'.Nicholas K Humphrey